CHICAGO (AP) -- As if air travel over the Thanksgiving holiday isn't tough enough, it could be even worse this year:  Airports might see even more disruptions because of a loosely organized Internet boycott of full-body scans.

Even if only a small percentage of passengers participate, experts say it could mean longer lines, bigger delays and hotter tempers.

The protest called National Opt-Out Day is scheduled for Wednesday to coincide with the busiest travel day of the year.

Participants are being urged to decline the scans, which take as little as 10 seconds. Instead, they would have to undergo a full pat-down, which takes much longer.  That could cause a cascade of delays at dozens of major airports.

Not all airports have the machines. And not all travelers are selected for scans.