Federal law prohibits passengers from interfering or physically assaulting (or threatening to physically assault) airline crewmembers.

This means injuring or intimidating a crewmember -- or attempting to do so -- can result in a felony conviction if the defendant has interfered with the performance of the crewmember's duties.

Flight crew interference incidents can result in up to 20 years' imprisonment and fines of up to $250,000, according to the Federal Bureau of Investigation.

Acts of interference that don't quite rise to the level of criminal conduct can still warrant hefty fines by the FAA.

In fact, the FAA can propose up to $25,000 per violation for unruly passenger cases. One incident can result in multiple violations, according to the FAA's website.

A slew of disruptive behaviors can be considered interference, including:

Flashing a laser beam from the ground;
Physically blocking crewmembers' access in the aisle or galley;
Threatening a crewmember; and
Disobeying crewmembers' repeated requests.