Did Muslims celebrate the attack on 9/11 in New Jersey in 2001?

Question

Donald Trump claimed this in November 2015:

"I watched in Jersey City, New Jersey, where thousands and thousands of people were cheering as that building was coming down. Thousands of people were cheering."_{New York Times}

He later specified:

It did happen. I saw it. It was on television. I saw it. There were people that were cheering on the other side of New Jersey, where you have large Arab populations. They were cheering as the World Trade Center came down_{factcheck.org}

The NYT article claims:

[A] persistent Internet rumor of Muslims celebrating in Paterson, N.J., was discounted by police officials at the time. A search of news accounts from that period shows no reports of mass cheering in Jersey City._{New York Times}

And factcheck concludes:

[T]here is no evidence of it, the celebrating was not on TV and did not involve "thousands and thousands of people."_{factcheck.org}

However, a month later, other websites report differently. For example breitbart states:

The DC Media has spent the last two weeks attempting to destroy Donald Trump with lies. Outright lies, and they are doing so in order to protect a 14 year-old cover up. Not only have eyewitnesses and contemporaneous reports proven Donald Trump 100% correct about Muslims celebrating 9/11, a just-uncovered local CBS News (WCBS-TV in New York) report completely vindicates Trump’s claim of “thousands and thousands” of Muslims celebrating the fall of the World Trade Center.
[...]
FACT: Donald Trump is now 100% vindicated. _{breitbart.com}

They post a CBS report, but it doesn't seem to show recordings of thousands of people celebrating, nor does it seem to talk about thousands of Muslims celebrating.

The political insider claims:

Now, Former New York Police Department Commissioner Bernard Kerik has vindicated Trump in his claims, noting that there were many post-9/11 celebrations by NYC-area Muslims.

As One American News reports, Trump was right!_{thepoliticalinsider.com}

The video seems to mention some reports about celebrations, but doesn't mention if these reports were confirmed, or if they involved thousands of Muslims.

My questions are:

• Did thousands of Muslims celebrate the attack on 9/11 in New Jersey?
• Was video of this celebration broadcast on TV?
• In case neither is true, is there proof of celebrations that involved more than a handful of people somewhere in the US?

Answer 1

This has been a widely debunked claim. At best, it is based on second- and third-hand reports of people seeing some people on the rooftops that they assume were Muslims and were celebrating.

• Snopes has a piece about it.

  Donald Trump insisted he witnessed television footage "thousands" of Muslims in New Jersey "cheering" the 9/11 attacks, despite the fact that claim was long since debunked.

  The article discusses many attempts to track down the source of these rumours, which found nothing, and discusses some theories about where these rumours might have originated from. It ends with a discussion of a newspaper excerpt Trump pointed to on Twitter in 2015:

  ...(originally published by the Washington Post on 18 September 2001) described individuals who "allegedly" celebrated the attacks on rooftops in Jersey City (indicating that the celebrations were rumored, not confirmed). Trump claimed to have seen "thousands and thousands" of individuals in New Jersey on television, footage that has long been cited in rumors but doesn't appear to exist and doesn't jibe with the material he cited. Finally, it's unlikely thousands of any group of people could physically congregate on a rooftop.

• Politifact has a piece about it. They give it the "pants on fire" rating.

  If thousands and thousands of people were celebrating the 9/11 attacks on American soil, many people beyond Trump would remember it. And in the 21st century, there would be video or visual evidence.

  Instead, all we found were a couple of news articles that described rumors of celebrations that were either debunked or unproven.

• The Washington Post has a (repeatedly updated) piece about it. They give it "four Pinocchio's"

  Trump says that he saw this with his own eyes on television and that it was well covered. But an extensive examination of news clips from that period turns up nothing.

  ...Neither can we find any examples of Trump previously talking about this. Here, for example, is an article in the New York Post interviewing Trump just eight days after the attack; he makes no mention of having witnessed the alleged celebrations. And in a foreword for a book titled “Where Were You On 9/11?,” Trump makes no mention of this: “I was in my apartment in the Trump Tower [on the morning of Sept. 11, 2001]. I knew what was happening because I can see downtown to the Financial district.”

Answer 2

The OP asks:

1. Did thousands of Muslims celebrate the attack on 9/11 in New Jersey?
2. Was video of this celebration broadcast on TV?
3. In case neither is true, is there proof of celebrations that involved more than a handful of people somewhere in the US?

I think that there is an implicit question underlying this post which must be answered ( intended by the OP or not ), which is why do Trump and so many mainstream Americans believe that there were large scale celebrations by Muslims in the United States, in general, and in New Jersey specifically?

It may be that what Trump ( and many others ) remember are the widespread celebrations among Palestinian Muslims in Israel ( or by Muslims in other parts of the world ) which were widely reported in the media at the time. Focusing specifically on the Palestinian celebrations, Snopes debunks rumors that videos of these celebrations were forged, and this New York Post article also discuss the issue:

Here are the facts, all of which are matters of public record. On the afternoon of Sept. 11, 2001, thousands of jubilant Palestinians took to the streets, chanting “God is great,” firing automatic weapons and handing out sweets to passers-by. The largest demonstration took place in Nablus in the West Bank, where some 3,000 marchers danced and cheered as guerrillas fired assault rifles and grenades into the air.

There are a few videos of the smaller celebrations that were published by Reuters and broadcast by various outlets like CNN, as noted by Snopes, however the videos of the larger celebrations which were filmed by the AP ( which acknowledges their existence ) were never broadcast, due to threats by Palestinian terrorist groups against it's reporters, as noted in the New York Post article.

I followed the link provided by the OP to the Breitbart site, and it appears there were at least a few small celebrations in various locations by American Muslims. The CBS news video the OP links to specifically mentions a small rooftop celebration in Jersey City reported by police, and the Breitbart site has been collecting what seem to be credible and specific reports of other small celebrations as reported for example by Dan Rather and former NYPD Commissioner Bernard Keirick.

It's quite likely that what Trump ( and many other people ) were remembering are the videos of the smaller celebrations by Muslims that took place outside the United States and were widely broadcast in the media at the time, plus the above listed credible reports of a handful of small celebrations by very small numbers of American Muslims, and are conflating them with the AP footage of the larger celebrations with thousands of people in Nablus, which were reported in the media at the time, but never broadcast.