I just learned about this, thanks to Gabriel Malor:

(Obligatory punctuation nod to the “blog” of “unnecessary” quotation marks.)
Here’s the text of the ordinance:
(a) For purposes of this section:
1. “Silly String” shall mean any putty-like substance that is shot or expelled in the form of string from an aerosol can or other pressurized device, regardless of whether it is sold under the name “Silly String” or any other name.
2. “Hollywood Division” shall mean the area defined by the Los Angeles Police Department as the Hollywood Division, the geographical boundaries of which include all of that portion of Los Angeles City bounded and described as follows: Beginning at the point of intersection of Beverly Boulevard and Normandie Avenue, and proceeding northerly along Normandie Avenue to Franklin Avenue, and proceeding westerly along Franklin Avenue to Western Avenue, and proceeding northerly along Western Avenue to Fern Dell Drive, and continuing northerly along Fern Dell Drive to its terminus, and proceeding due north through Griffith Park to Forest Lawn Drive at its intersection with Zoo Drive, and proceeding westerly and southwesterly along Forest Lawn Drive to Barham Boulevard, and proceeding southerly along Barham Boulevard to United States Highway 101, and proceeding southeasterly along U.S. Highway 101 to Mulholland Drive, and proceeding westerly along the various curves and courses of Mulholland Drive to the Crest of Ridge, and proceeding southerly following the Los Angeles city line along the eastern border of the Trousdale Estates area of the City of Beverly Hills to the northeast corner of the City of West Hollywood, and proceeding easterly following the Los Angeles city line bordering along its various curves and courses of the northern border of the City of West Hollywood to the eastern border of the City of West Hollywood that is to the east of La Brea Avenue, and proceeding southerly along the Los Angeles city line to Romaine Street, and proceeding westerly following the Los Angeles city line along its various curves and courses to the intersection of Romaine Street and La Cienega Boulevard, and proceeding southerly following the Los Angeles city line along its various curves and courses to Beverly Boulevard, and proceeding easterly along Beverly Boulevard to La Brea Avenue, and proceeding northerly along La Brea Avenue to Willoughby Avenue, and proceeding easterly along Willoughby Avenue to Hudson Avenue, and proceeding southerly along Hudson Avenue to Melrose Avenue, and proceeding easterly along Melrose Avenue to Gower Street, and proceeding southerly along Gower Street to Beverly Boulevard, and proceeding easterly along Beverly Boulevard to Normandie Avenue.
3. “Halloween” shall mean the 36-hour period from 12:00 a.m. on October 31st of each year, through 12:00 p.m. on November 1st of each year.
(b) No Person, as defined in Municipal Code Section 11.01(a), shall possess, use, sell or distribute Silly String at, within or upon any public or private property that is either within public view or accessible to the public, including, but not limited to, public or private streets, sidewalks, parking lots, commercial or residential buildings, places of business, or parks within the Hollywood Division during Halloween.
(c) Any violation of this section is a misdemeanor subject to the provisions of Los Angeles Municipal Code Section 11.00(m).

latinist says:
The Second Amendment is under attack!
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November 4, 2009, 7:03 pmjhubme_24 says:
what about daylight savings?
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November 4, 2009, 7:07 pmgasman says:
I’m sort of curious as to why the term person might need to be defined, and just how they define it...
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November 4, 2009, 7:10 pmDjDiverDan says:
OK, so Silly string is out — But my flaming paper bag of dog poop is fine, right?
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November 4, 2009, 7:13 pmYankev says:
This means criminalizing nearly every frum wedding if it’s held in LA during that 36 hour period. Not only the Second Amendment, but the First, is under attack!
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November 4, 2009, 7:14 pmYankev says:
That’s probably defined by State law, so that whichever time is then in effect would govern.
But you already knew that.
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November 4, 2009, 7:17 pmjhubme_24 says:
Especially in light of its potential for use in self-defense!
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November 4, 2009, 7:18 pmSplunge says:
But any fool knows the real Hallowe’en threat is toilet papering.
Has the LA City Council considered banning the possession, use, sale or distribution of toilet paper in the 36 hours surrounding Hallowe’en? I think they should.
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November 4, 2009, 7:30 pmMark N. says:
I believe there are a number of municipalities that completely ban silly string year-round, as well.
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November 4, 2009, 7:30 pmsome guy in ohio says:
Yankev — under current Federal guidelines for DST, the specified time period is 37 hours long, not 36.
[Edit] Any year where Nov 1 falls on a Sunday, I should clarify.
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November 4, 2009, 7:33 pmRob Jerram says:
With reference to “3. “Halloween” shall mean the 36-hour period from 12:00 a.m. on October 31st of each year, through 12:00 p.m. on November 1st of each year.”, I think (maybe) jhubme_24 was wondering whether or not the period from 12:00am on 10/31 through 12:00pm on 11/1 a period of 37 hours? Didn’t we replay one of those hours in the early morning of 11/1 due to the resumption of standard time? You know, the part where we “fall back” one hour?
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November 4, 2009, 7:35 pmPatHMV says:
Is there a rational basis for this action to infringe upon our unenumerated right to buy, sell, and use Silly String?
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November 4, 2009, 7:35 pmMike McDougal says:
Don’t try to extend my suffering by 2.8%.
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November 4, 2009, 7:36 pmAbdul Abulbul Amir says:
Whatever the problems of silly string, the stuff is not as bad as a squirt gun loaded with French’s yellow mustard.
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November 4, 2009, 7:46 pmChrisTS says:
Well, I don’t think so, so the Court should toss it.
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November 4, 2009, 7:48 pmzuch says:
This is plainly unconstitutional. The right to KABA should cover this ... the right to keep and bear amusements, that is. And this applies in particular to concealed carry.
Cheers,
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November 4, 2009, 7:52 pmNathan says:
When silly string is outlawed, only outlaws will have silly string.
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November 4, 2009, 7:53 pmChrisTS says:
On the other hand, how many of us have had to clean this stuff up after it dries?
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November 4, 2009, 8:20 pmChrisTS says:
zuch:
As you are over here, I need you to scold me: I let loose on our favorite troll on Balkanization.
I should be covered in silly string.
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November 4, 2009, 8:21 pmYankev says:
Sorry, I missed the fall back issue, as some guy in Ohio (Columbus?) pointed out.
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November 4, 2009, 8:25 pmCato The Elder says:
Isn’t Silly String particularly flammable?
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November 4, 2009, 8:28 pmApu Nahasapasapeemipetilon says:
I’m mad the Safeway by my house didn’t have 2 for 1 deals on eggs on Halloween like they usually do. I usually make huge omelets on the 1st.
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November 4, 2009, 8:30 pmeyesay says:
It’s amazing how many editing errors there are on a six-line sign.
1. Space between dollar sign and dollar amount
2. First line is quoted for no reason
3. Quote at end of first line is an open quote instead of close quote
4. No space between 12:00 and AM
5. 12:00 AM is ambiguous as to whether it is at the beginning or the end of October 31; use of 12:01 AM is preferred
6. No space between 12:00 and NOON
7. 12:00 NOON is redundant; NOON suffices
8. NOVEMBER 1ST is an ordinal date; should use a cardinal date both in general and to be consistent with OCTOBER 31
9. Quotes around ILLEGAL serve no purpose and imply that the illegality is figurative or in some way less than normal
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November 4, 2009, 8:32 pmkimsch says:
Wouldn’t Easy Cheese fall under this definition?
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November 4, 2009, 8:46 pmStringTheory says:
What if I need to detect tripwires?
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November 4, 2009, 8:58 pmEH says:
it’s tough but fair.
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November 4, 2009, 9:05 pmkrs says:
This is the same jurisdiction that punishes repeat celebrity DUI with 2–10 hours in jail, more or less on the honor system, no?
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November 4, 2009, 9:18 pmBruce Boyden says:
Now that’s what I call narrowly tailored.
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November 4, 2009, 9:20 pmjccamp says:
“$1,000.00 FINE”
SILLY
STRINGTHREAD PROHIBITED12:00 AM OCTOBER 31 to
12:00 NOON NOVEMBER 1st
You’re OK. The statute of limitations has run...
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November 4, 2009, 9:50 pmChrisTS says:
That, plus putative edibility, must mark the differentiation between Silly String and Easy Cheese. Otherwise, I’m at a loss.
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November 4, 2009, 10:10 pmTweets that mention The Volokh Conspiracy » Blog Archive » L.A. Halloween Silly String Ban -- Topsy.com says:
[...] This post was mentioned on Twitter by Walter Olson and Joe Brooks, Gabriel Malor. Gabriel Malor said: Oop. Got blogged over at Volokh Conspiracy: http://is.gd/4NqqC [...]
David Nieporent says:
If it plays its cards right, it could run for city council.
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November 4, 2009, 10:38 pmMalvolio says:
12 PM? There’s no such time. PM is post meridian, “after noon”.
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November 4, 2009, 11:12 pmkrs says:
Malvolio, do you represent tax protestors?
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November 4, 2009, 11:40 pmgullyborg says:
Suppose I spray Silly String on a burning American Flag?
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November 5, 2009, 12:49 amKirk Parker says:
kimsch,
That’s a feature not a bug.
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November 5, 2009, 1:23 amuberVU - social comments says:
Social comments and analytics for this post...
This post was mentioned on Twitter by gabrielmalor: Oop. Got blogged over at Volokh Conspiracy: http://is.gd/4NqqC...
James says:
Most likely banned b/c of its flammability. (When combined with the lack of knowledge of said “flammability”, + Large numbers of people, + the large numbers of people being drunk)........
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November 5, 2009, 4:51 amSonicfrog says:
Isn’t Los Angeles running in the red? How much did printing these signs cost????
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November 5, 2009, 9:31 amMatthew X. Economou says:
Wouldn’t laws against littering be sufficient to stop people from using silly string in public? Would anti-littering laws still be constitutional/reasonable if they included a fine schedule that increases the fine based on the difficulty of cleanup or volume of litter?
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November 5, 2009, 9:35 amSome dude says:
Corporations are not exempt. If you see a corporation walking down the street flinging silly string, they are liable for a fine.
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November 5, 2009, 10:27 amBED says:
So, there’s nothing to stop wily teens from spraying silly string all over this sign up until 12:00 on Oct. 31? Why wouldn’t they do that instead? Especially since the 30th was a Friday this year.
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November 5, 2009, 11:07 amKevin P. says:
And the same jurisdiction that can’t be bothered to effectively crack down on taggers who vandalize private property with graffiti, but fines the owners of the said private property if they don’t remove the graffiti at their own expense.
Link
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November 5, 2009, 12:25 pmray_g says:
Seriously, stuff like this is why for years I have turned a deaf ear to any and all requests to vote for initiatives, taxes, bonds, candidates or whatever that want to increase funding for law enforcement. If they have time to worry about this kind of thing, they don’t need any more money.
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November 5, 2009, 12:44 pmDotar Sojat says:
What about Silly String Theory?
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November 5, 2009, 2:08 pmtraveler496 says:
I’d still like to know whether one could escape the fine by correctly pointing out that 2009 had no Halloween in the Hollywood Division. But not quite enough to try the experiment next year (which will also have no Halloween in the Hollywood Division:-)
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November 5, 2009, 6:17 pmSeamus says:
Well, then, that means that 12 pm is midnight. (And so is 12 am).
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November 5, 2009, 6:37 pmtraveler496 says:
I take it back: Next year, there will be Halloween in the Hollywood Division (I had erroneously convinced myself that Hollywood Division has Halloween only five-sevenths of the time rather than six-sevenths). So the next chance to do the (probably ill advised) experiment won’t be until 2015.
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November 5, 2009, 8:24 pmSJN says:
For what it’s worth, the standard-form contract for inflatable
bounce-house rental also requires the adult renter to prevent
all children from bringing silly string into the bounce house.
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November 5, 2009, 10:40 pmSteveW says:
The definition of “silly string” would include the aerosol version of Cheez Whiz.
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November 6, 2009, 12:45 pmNovember 6 roundup says:
[...] Possession, not just wrongful use: “L.A. Halloween Silly String Ban” [Volokh] [...]
Robert S says:
Since we’re getting so nitpickey here, Malvolio’s comment that there is no such time as 12 PM is wrong; it simply means noon. And PM does not stand for post-meridian, but for post-meridiem, which means after the middle of the day, and has nothing to do with meridians.
And I challenge eyesay’s point #5 that says that 12:00 AM is ambiguous and could be taken for the beginning or the end of a given day. Each day has only one 12:00 AM, and it is the first minute of that day. Where is the ambiguity?
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November 6, 2009, 3:24 pm