The New York Police Department has demanded that Twitter release the name of a user who threatened an attack "just like in Aurora" on the Broadway theater where Mike Tyson's one-man show is playing.
The NYPD plans to subpoena Twitter today for the user's identity after the social media giant refused authorities' emergency request for the information.
"This s**t ain't no joke yo I'm serious people are gonna die just like in aurora," the user tweeted Aug. 1.
A few days earlier, the unidentified person tweeted that he or she knew that the theater left its exit doors unlocked and was going to plan the shooting "step by step."
The NYPD Intelligence Division learned of the threat late Aug. 3 and used Twitter's system for emergencies to request the identity of the account holder, according to police officials.
"Twitter turned us down, so we dispatched police to cover the theater while we sought a subpoena to force Twitter to disclose the identity of the account holder," NYPD spokesman Paul Browne said in an emailed statement.
Police officers were dispatched to New York's Longacre Theater where Mike Tyson's one-man show, "Undisputed Truth," is playing.
"We take the threat seriously, especially in light of recent attacks in Wisconsin and Colorado," Browne said.
Alleged shooter Wade Michael Page killed six people Sunday at a Sikh temple in Oak Creek, Wis. Page, an Army veteran, was shot dead by police. Two weeks earlier, on July 20, suspected shooter James Holmes opened fire in a packed midnight showing of "The Dark Knight Rises" in Aurora, Colo., killing 12 people and injuring 58.
Following email requests for comment from ABCNews.com, a spokeswoman for Twitter wrote, "We don't have a comment on this." She also sent a link to Twitter's guidelines for law enforcement.
"Twitter evaluates emergency disclosure requests on a case-by-case basis," the guidelines say. "If we receive information that gives us a good faith belief that there is an emergency involving the death or serious physical injury to a person, we may provide information necessary to prevent that harm, if we have it."
The guidelines also say that the release of private information "requires a subpoena or court order."
If Twitter were to turn over the user's identity at the first request, it could be liable for any mistake or potential invasion of privacy, according to Jennifer Granick, the director of civil liberties for Stanford Law School's Center for Internet and Society.
"The law prohibits providers from turning certain information over voluntarily and, if they do, they can be sued," Granick said. "But the government can compel the information from the provider with varying degrees of legal process depending on what the information is. When it's the name associated with the account, the government can get that with just the subpoena."
The federal law is part of the Electronic Communications Privacy Act, passed in 1986. There are exceptions to the law, Granick said. Exceptions can be made if there's a threat of serious bodily injury or death. But that first decision is up to the provider.
When another Twitter user asked the threatening tweeter on Aug. 3 whether he or she had undergone a change of heart about the prospective shooting at the Midtown Manhattan theater, the person replied, "no I had last minute plans and I'm in Florida rite now but it'll happen I promise I'm just finishing up my hit list."
The Twitter user makes frequent references to his or her "hit list," making threats against many celebrities, including Ellen Page, Perez Hilton, Wendy Williams and several members of the Kardashian family.