CHAMPAIGN, Ill. — Comcast Cable Communications must identify an Internet-service subscriber who posted an anonymous message suggesting a political candidate molests children, the Illinois Supreme Court ruled Thursday.

The decision comes as concerns rise about potentially damaging online comments made anonymously, and affirms what many legal experts say seems to be lost on online commenters: Their anonymity doesn’t protect them if their comments could be considered defamatory.

But attorney Robert Fagan, who is representing the anonymous subscriber, hopes Thursday’s decision isn’t the final word, and believes his client will ask the U.S. Supreme Court to hear his case before the 90-day window is up.

“There are certainly First Amendment issues and defamation issues which should bring this to their attention,” Fagan said.

Fagan’s client commented on a 2011 article in the Freeport (Ill.) Journal Standard about Bill Hadley’s candidacy for the Stephenson County board.

“Hadley is a Sandusky waiting to be exposed. Check out the view he has of Empire (Elementary School) from his front door,” wrote the commenter, who used the online name “Fuboy.” The comment was a reference to former Penn State football coach Jerry Sandusky, who was convicted of numerous counts of child sex abuse in 2012.

Hadley, a 57-year-old retired Illinois Department of Corrections officer and chairman of the county board, said he had spent more than $30,000 pursuing the case over a vague accusation implying a crime he was never charged with or otherwise accused of committing.

“For 3½ years I’ve been trying to get the name, the identity of this person,” he said in an interview Thursday. “It’ll be a huge victory for me, but it’s practically broke me financially.”

Hadley plans to pursue the defamation lawsuit as soon as he can, pending the anonymous commenter’s next steps, said Andrew Smith, Hadley’s attorney.

The Illinois Supreme Court’s decision was similar to rulings elsewhere in the country, said University of California-Irvine law professor Jack Lerner. “This has been litigated in many if not all states,” he said.

Other legal experts said they’re often surprised that people who comment online, even younger Internet users who have grown up online, seem to believe they’re protected.

“In my experience with speaking with groups, and even speaking with some students, they seem to believe they will be protected when they speak on the Internet because they choose to use some fictitious name,” said Tulane University law professor Amy Gajda.

Illinois’ opinion was based in large part on a pair of earlier lower-court decisions in the state, which held that the anonymity of someone who makes comments in response to online news stories isn’t guaranteed if their opinions are potentially defamatory, said Don Craven, an attorney for the Illinois Press Association.

“It’s not that you get to say whatever the heck you want to say and you’re going to remain anonymous,” Craven said.