Neil Cavuto reported on "Your World" that the FBI is investigating a series of bomb threats made against a number of U.S. flights over the weekend. 

Cavuto explained that five separate planes were forced to land or taxi away from the gates this weekend due to threats received.

Associated Press reported:

Two planes were evacuated upon arrival at Seattle-Tacoma International Airport on Sunday due to what a spokesman called a "security concern."

Airport spokesman Perry Cooper says a JetBlue flight from Long Beach, California, and a regional SkyWest jet from Phoenix were the planes involved. The flights arrived late Sunday afternoon.

Cooper said that as a precaution, passengers were bused to their gates from the airport's third runway. He said the matter was under investigation and that he did not have further details.

Additionally, a Delta Air Lines spokesman says a flight from Los Angeles to Orlando was diverted to Dallas Sunday afternoon due to "a security concern."

Former U.S. Air Marshal Jonathan Gilliam told Cavuto that there is a reason for the increase on threats.

"How can we expect for people not to make threats or to take the law seriously, if we're doing things like [...] letting convicted terrorists who are combatants of war go home for good behavior?" Gilliam asked. "It makes no sense."

He said that that is emboldening this type of increased threats that the country has been seeing.

"It's the same thing with any other law, the drug laws, anything," Gilliam said. "Once you stop enforcing the laws, once you stop handling down the maximum penalties, people stop taking it seriously."

Gilliam warned that the country will experience more and more of this. 

Watch the video above.