OK, this wasn't funeral picketing as such, and it was a bit less outrageous than Phelps' picket signs. But only a bit.
George Beals, age 19, died of a lingering and painful disease, possibly tuberculosis ("consumption"). His father arranged an obituary in a Universalist newspaper, which said,
He was a pattern for the imitation of the rising generation.--He was one who always detested the use of ardent spirits;--he never allowed himself to use vulgar or profane language, and avoided the company of those who did;--he was modest and genteel in his deportment, and gained the love and affection of all who had the pleasure of knowing him.--He never professed any particular tenet of religion, but listened to all.--His sickness was long and tedious. He had many friends who felt anxious for his future fate; and often inquired whether he was prepared for a future state.--He invariably answered them, I know of no action of my life, which causes me the least anxiety;--and God is above the Devil, what have I to fear?--He died as he lived, sensible to the last, full of faith and hope.
Two weeks later, Origen Bacheler, the owner and editor of the Anti Universalist newspaper, decided to publish a rebuttal to an obituary (I italicize the allegedly libelous portion):
VERACITY OF THE TRUMPET.
The Trumpet of the 10th inst. contains an obituary notice [describing the above notice] .... Now we are authorized to say, that this person, instead of being an example to others, and being free from the use of profanity, was actually habituated to it; that he was known to believe in Universalism; that, on his death bed, instead of saying that God was stronger than the Devil, he renounced Universalism, and gave evidence of a gracious change.
By the foregoing, the public will learn to receive the obituaries of the Trumpet with many grains of allowance....
Lovely: A young man dies, and a stranger's religious fanaticism (apparently shared by the young man's younger brother, who was the source for the rebuttal) leads the stranger to try to publicly correct the young man's obituary by accusing him of sinful conduct. As the prosecutor in the criminal libel prosecution of Bacheler put it, in flowery but sound language, "It was rarest of all that the most vile, the most malignant, the most daring, would strip off those little flowers which the hand of affection had strewed over the grave of their loved one, and scatter in their stead the rank weeds of opprobrium and disgrace."
The test for a criminal libel at the time was that a defamatory statement was libelous unless it was true, and was made with good motives and for justifiable ends. To my surprise, the jury rendered a not guilty verdict, though "requesting [the judge] to state to Mr. Bacheler that although they had brought him in not guilty, yet they did not approve the course which he had taken ..., but had acquitted him on the ground, that they did not think he had any particular malice against the deceased."
Source: Trial of the Commonwealth, Versus Origen Bacheler, for a Libel on the Character of George B. Beals, Deceased, at the Municipal Court, Boston (Boston, John H. Belcher 1829).