Protesters gather for candle light vigil, protesting over the August 9 police shooting of Michael Brown, outside the Ferguson Police Department in Ferguson, Missouri, November 21, 2014.

Many have been wondering if the threats of violence related to the Michael Brown/Darren Wilson grand jury announcement are a legitimate concern, or if they are just rhetoric, as were the threats of rioting after the George Zimmerman verdict. The threats of violence in Florida never materialized to any significant degree.

Some news outlets think that many protesters who spontaneously demonstrated in Ferguson in August will stay home when the grand jury decision is made to avoid the troublemakers and agitators, and perhaps more importantly, past victims who are now ready to repel violence with force.

Some said they have heard the stern pronouncements of law enforcement agencies and seen reports of business owners arming themselves and boarding up their shops, and were scared by them.

“Basically, you doing what you did before, it’s suicide,” said Aaron Davis, 30, a barber from Ferguson who was a regular during the summer protests but avoided the violence. “Let’s be real about it. You know when you go out there, it’s over. They’re ready for you.”

Much of the talk, on the street and online, about confronting police officers is just empty boasting, several young men said. Time and again, Mr. Davis said, he has heard people come into his barbershop warning that things will get out of control. But, he said, he has not heard one person say he will actually partake in violence.

Hopefully the peaceful protesters from this past summer like Mr. Davis will opt to remain home or will participate again in non-violent protests… out of a desire for self-preservation, if for no other reason.

The FBI arrests of  New Black Panther members Brandon Orlando Baldwin and Olajuwon Davis, however, suggests that there is an intent to commit violence  from some radicals.

Against this backdrop of heightened tensions, according to a law enforcement source, two men described as reputed members of a militant group called the New Black Panther Party, were arrested in the St. Louis area in an FBI sting operation.

As initially reported by CBS News, the men were suspected of acquiring explosives for pipe bombs that they planned to set off during protests in Ferguson, according to the official, who spoke to Reuters on condition of anonymity because he was not authorized to publicly discuss the case.

The official said the two men are the same pair named in a newly unsealed federal indictment returned on Nov. 19 charging Brandon Orlando Baldwin and Olajuwon Davis with purchasing two pistols from a firearms dealer under false pretenses.

Both men were arraigned on Friday in federal court, the law enforcement source said.

I’m not sure what special sort of idiot goes shopping for pipe bombs, but unverified news accounts suggest that the two would-be terrorists were plotting to take down the iconic Gateway Arch in St. Louis pipe bombs.

Engineers they clearly are not.

The second set of charges revolved around the purchase of a pair of Hi-Point .45 ACP pistols through a straw-purchaser.

It seems safe to assume that the FBI had agents or informants in both the pipe bomb and straw-purchasing plots, since no one else was arrested other than the two New Black Panther members. The FBI did not consider these two masterminds especially dangerous, and indeed it seems obvious that they weren’t very bright.

Some news media accounts said last night that grand jury announcement would come Sunday evening, but officials have quashed those claims—at least for now—and won’t even say if the grand jury has completed their investigation.

One St. Louis area school district has already canceled the remaining classes for the upcoming Thanksgiving holiday week in anticipation of unrest when the jury verdict is delivered.

The FBI, DHS, and other law enforcement agencies have brought significant assets to the St. Louis area to try to ensure that there is enough of a law enforcement presence to stop the sort of rioting that we saw over the summer.

The question still remains as to whether law enforcement agencies in dozens of other cities who plan Ferguson decision protests are adequately prepared to ensure that those protests remain non-violent.