When the FBI asked for help from the media and the public on Thursday in its manhunt for suspects in the Boston bombing, the Twitterverse immediately got to work – spreading photos, videos and phone numbers to call. But by Friday, all that activity had given way to another concern: Could social-media threaten investigators' ability to capture the main suspect still at large?
The public has never had such an up-close, play-by-play account of a manhunt, with instant updates from people – both professional journalists and citizens – on the scene. Indeed, the story has dominated social media: Up to 8 of the top ten world-wide Twitter trends on Friday have been directly related to the Boston investigation.
(Read More: Terror Experts Analyze Boston Manhunt)
Even the shootout and stakeout of the suspects during the early hours of Friday was captured by regular tweets from people on the scene in Watertown, Mass., including a professor at the Massachusetts Institute of Technology, as well as a journalist (@sethmnookin) who wrote about gunshots and shared images of cops and FBI agents on the scene. A number of Watertown residents, including entrepreneur Andrew Kitzenberg (@AKitz), also posted photos on Twitter of the shoot out and SWAT teams.
(Read More: Suspects Told Carjack Victim They Were Bombers)
But experts say that rapid spreading of information could backfire by aiding the very suspects authorities are trying to capture. The Boston PD is urging people not to tweet details of which homes are being searched, as that might compromise their efforts. (@Boston_Police tweeting: #MediaAlert: WARNING: Do Not Compromise Officer Safety by Broadcasting Tactical Positions of Homes Being Searched.)
In addition, authorities have asked citizens to stop tweeting updates from Boston police scanners. Thousands of people have listened to the events play out over the police radio airwaves. On Friday morning, the Boston police and FBI requested that the media and the public stop broadcasting scanner traffic.
A Twitter account for the surviving suspect was created Friday morning. There has been much speculation on the social-media network about where the account is real or a fake. (Twitter declined to comment.). The account, @Dzhokhar_A, has drawn more than 6,000 followers so far. (Sample tweets: "I will kill you," and "@Boston_Police Do not approach.")
But that's not the only Twitter account linked to Dzhokhar Tsarnaev, otherwise known as "Suspect 2." An account with the name 'Jahar,' and the Twitter handle @J_tsar has been linked to him — and he was widely reported as going by the name "Jahar." There are various things that tie the suspect to this account, including comments about being Chechen, and an old picture that looks like him.
The last tweet from the account was on April 17, but on the day of the attack and the day after he sent some disturbing tweets. On Monday, he tweeted "@MelloChamp and they what "god hates dead people?" Or victims of tragedies? Lol those people are cooked." The day after the attack he tweeted, "So then I says to him, I says, relax bro my beard is not loaded."
With reports swirling that @J_tsar is the suspect, the account's number of followers has increased to more than 28,000.
—By CNBC's Julia Boorstin; Follow her on Twitter: