New York - CNN says safety concerns led to its decision not to reveal the identity of the man behind a doctored anti-CNN video. Yet the way the decision was explained and deep distrust of the network among President Donald Trump's supporters provoked a backlash on Wednesday.The network said late on Tuesday it had identified the Reddit user who originally posted an old WWE video of Trump "roughing up" pro wrestling maven Vince McMahon, superimposing the CNN logo over McMahon's face. Trump tweeted a link to the video, with some modifications, and it has become the president's most-shared social media post yet, according to Twitter.Reporter Andrew Kaczynski said in an online story that CNN had found the Reddit user, who used the tag "HanA------Solo," and reached out to him on Monday. Before returning Kaczynski's message the next day, the user posted a public apology for the Trump video — he called it a prank — and for some racist and anti-Semitic postings also made under that name. He said he was just trying to get a reaction and didn't mean what he said, and was closing his Reddit account.BlackmailCNN said online that it had decided not to publish the user's name because he is a private citizen who apologised, showed remorse and said he would not repeat his ugly behavior. "CNN reserves the right to publish his identity should any of that change," Kaczynski wrote.That last sentence made CNN a target."That's essentially blackmail," wrote conservative activist Ben Shapiro. "That's CNN stating that it will out the guy if he dares to defy their political perspective or offends them sufficiently."Such charges spread swiftly online. Fox News Channel host Sean Hannity shared another video on Twitter, this one showing a professional wrestler whose face was replaced with a Trump picture bashing several other men identified as "CNN" with a chair. "Is CNN going to blackmail this person, too?" Hannity asked.CNN said on Wednesday that it did not publish the user's name out of concern for his safety, and that any claim that it tried to blackmail or coerce him was false. Kaczynski tweeted that the user told him he had not been threatened in any way.CNN's online critics, including Donald Trump Jr., claimed the Reddit user was a 15-year-old boy. CNN said he was an adult male and Kaczynski tweeted, "People claiming he's 15 are wrong."Hidden identityThe video sent out by Trump on Sunday morning had been retweeted more than 340 000 times by Wednesday morning. That passes Trump's tweet the morning of last November's election — "TODAY WE MAKE AMERICA GREAT AGAIN! — as his most-shared post, Twitter said.CNN also received heat from another direction for its decision to withhold the user's name.There are many reasons to keep a name out of a story, said William Grueskin, a Columbia University professor. The person could be an abuse victim, a confidential witness whose life or job would be endangered, a source promised anonymity or a juvenile. The Reddit user "doesn't appear to fit any of these categories," he said."That puts a high expectation on other reporters, who are asked every day to withhold names and who don't, for good reason," he said. "Are others now supposed to engage in a negotiation with sources that illustrates moral probity and predicts future conduct?"Indira Lakshmanan, an expert on journalism ethics for the Poynter Institute, said she has no problem with CNN finding out the user's identity, since the person put his opinions in the public square and boasted about the president's retweet.She said it's more likely the user pleaded with CNN to have his name withheld out of fear than the network trying to blackmail him in any way.Still, she said, the network could have explained its decision better and the "reserves the right" claim is unnecessarily problematic.