Coleman told Henriquez he was spared a longer prison term only because he accepted responsibility by pleading guilty to witness intimidation, had no criminal record, and worked full-time for a landscaper.
"Nothing in the world is more dangerous than sincere ignorance and conscientious stupidity," Coleman told Henriquez, quoting Martin Luther King Jr. "Nothing is more serious in this day and age."
As part of the sentence, Coleman barred Henriquez from using social media sites on the Internet except for "work or for learning purposes."
Court officials say witness intimidation is an epidemic in Philadelphia's criminal justice system.
An Inquirer series about the Philadelphia courts in 2009 reported that prosecutors charged about 1,000 people with witness intimidation between 2006 and 2008. Prosecutors won convictions in only 28 percent of resolved cases.
Since District Attorney Seth Williams took office in 2010, his office has prosecuted 1,045 people for witness intimidation.
In February, Henriquez became the focus of a public dispute between Williams and Facebook over whether it should be a "good corporate citizen" and remove Henriquez's Facebook page.
Facebook officials publicly rejected Williams' request and said Henriquez had not violated its user rules. Still, within a day of Williams' news conference, Henriquez's objectionable Facebook pages were gone.
According to Assistant District Attorney Andrew Wellbrock, a Holmesburg gun seller last year reported what he believed were suspicious gun purchases by a young woman.
In February 2012, the woman was charged with making straw purchases: buying guns for convicted felons. The woman, who prosecutors decline to name, gave police a statement and agreed to testify against her clients.
One customer, David Ruiz, 22, gave Henriquez the woman's eight-page police statement, and Henriquez posted it on Facebook with his suggestion for dealing with her.
Ruiz, 22, was arrested Jan. 11 on gun charges as part of the straw-purchase probe. Wellbrock said Ruiz pleaded guilty June 19 to making false statements to illegally acquire guns and was sentenced to one to two years in prison and four years' probation.
Wellbrock argued for a prison sentence of two to four years for Henriquez, saying witness intimidation makes "the justice system grind to a halt."
"He posted a wanted poster on the Internet, and, in this case, he wanted her dead," Wellbrock said.
Defense attorney Louis T. Savino Jr., however, called Henriquez an "impressionable young man" and his conduct "stupid," but added that two presentence reports called him a good candidate for probation and work-release.
Savino urged Coleman "not to get involved in this so-called Internet frenzy."
Coleman's sentence lets Henriquez participate in work-release while serving his prison term.
Contact Joseph A. Slobodzian at 215-854-2985, firstname.lastname@example.org, or @joeslobo on Twitter.