Federal authorities are on alert, more police have been deployed and security teams have been are sweeping popular Fourth of July destinations because of concerns about a terrorist attack.

Recent terror attacks in France, Tunisia and Kuwait are a bloody reminder that jihadist violence is global, with varied targets and tactics that are difficult for even the most adept security forces to counter.

And while the front lines of Iraq, Syria and other hot spots are distant from U.S. shores, America is still a favorite symbolic target for jihadist terrorism. As is so often repeated, it seems only a matter of time before we are hit again, and some are suggesting that time is almost here.

As Independence Day celebrations begins, government agencies are issuing vague but unnerving warnings about a possible terrorist threat targeting America over the Fourth of July weekend.

"ISIS is very well outspoken about how much they hate our freedom, who we are as Americans and July the fourth is one of those natural dates while we're celebrating freedom for them to try and poke us in the eye.," said San James Lankford, R-Oklahoma, a member of the Senate Committee on Homeland Security and Government Affairs.

As Americans begin their holiday weekend celebrations, they'll be mindful that the Department of Homeland Security, FBI and the National Counterterrorism Center have issued a bulletin to law enforcement across the country warning of the possibility of an imminent strike against the United States. The FBI is establishing command centers to monitor the threat and closely coordinating with local police. Intelligence agencies are watching as online chatter rises.

While they sound ominous, many of these warnings and precautions are also pretty routine. Any holiday weekend, and especially the Fourth of July, is a ripe target for a terrorist attack since more civilians travel and there are large ceremonial gatherings. In fact, we already suffered an act of terrorism on July 4, 2002, when an Islamic terrorist shot up Los Angeles Airport's El Al ticket counter, killing two Israelis.

While the terror threat centers around ISIS-inspired attackers, many in the intelligent community say there is no evidence of a specific credible plan.

"I would not alter your plans this holiday," said CNN analyst Mike Rogers, a former Michigan congressman who was chairman of the Permanent Select Committee on Intelligence. "I don't believe it's that serious. I do think it's serious enough that they're worried that someone will self-activate and try to do something."