A former journalist has been arrested on suspicion of making threats against Jewish community centres - in a bizarre plot against an ex-girlfriend.
Juan Thompson, 31, "allegedly caused havoc, expending hundreds of hours of police and law enforcement resources", said NYPD Commissioner James P O'Neill.
New York prosecutors said he was "stalking a former romantic interest".
The Missouri man was allegedly behind eight of some 100 threats to Jewish Community Centers (JCC) this year.
Mr Thompson was arrested on Friday in St Louis, Missouri, and will be in court later in the day.
As well as the threats against the JCCs in January and February, he is also accused of emailing a threat in his ex-girlfriend's name to the Anti-Defamation League (ADL) in New York City.
The next day the offices of the Jewish anti-bigotry group received a phone call claiming that explosive material had been placed inside the building.
"Today, we have charged Juan Thompson with allegedly stalking a former romantic interest by, among other things, making bomb threats in her name to Jewish Community Centers and to the Anti-Defamation League," New York-based US Attorney Preet Bharara said in a statement.
A spokesman for the White House said "it's still too early for us to say too much about it, but the process worked".
Mr Thompson is accused of cyber-stalking his ex-girlfriend - known in court documents as Victim-1 - which can carry a sentence of up to five years in jail.
He is also alleged to have made threats using his own real name, in a ploy to make it look like she was trying to frame him.
On 7 February, he allegedly wrote an email to the JCC offices in Manhattan, saying: "Juan Thompson put two bombs in the office of the Jewish center today. He wants to create Jewish newtown tomorrow."
This was a reference to the 2012 school shooting in Connecticut in which a gunman murdered 26 people.
In several tweets presented by investigators, Mr Thompson repeatedly accused his former girlfriend of making bomb threats in his name, in order to pin the crime on him.
He claimed she had hacked his email account.
"[Victim-1], though I can't prove it, even sent a bomb threat in my name to a Jewish center, which was odd given her antisemitic statement," he posted on 24 February 2017.
He also made several posts condemning the anti-Jewish threats.
It was allegedly part of a months-long campaign against his former partner after they broke up in July 2016.
Thompson began by sending an email to her manager at a New York-area social service organisation.
The message claimed she had been pulled over for drunk driving and sued for spreading a sexually transmitted disease.
He allegedly went on to threaten to publish nude photos of the woman, before escalating to the bomb threats this year.
On 24 February, he posted on Twitter: "Y'all know how to get a social worker in NY barred? I'm being stalked and harassed by a white nasty white woman."
Mr Thompson was fired last year from the Intercept, a news website, over "fabricated sources and quotes in his articles".
Intercept management released a statement on Friday saying they were "horrified" to learn about the arrest, and that they condemn the "heinous" threats.
At least 100 phone threats have been made to Jewish centres, childcare facilities and schools in three dozen states since the beginning of January, according to the JCC Association of North America.
Three Jewish cemeteries, including one near St Louis, have also faced vandalism attacks.