I've seen people do PLENTY of weird stuff on planes.  But this makes "taking off your shoes and putting your bare feet on the seat in front of you" look normal.

There's a 44-year-old guy named Matthew Flaherty, and he was on a flight last year from London to Iceland.  And he was drinking STRAIGHT GIN out of the bottle and got extremely drunk.

He started hitting on a female passenger, and when she ignored him, he started cursing her out and screaming he was going to kill her family.  Then he shouted more death threats at the flight crew.

Then . . . he took his cell phone apart and started EATING THE PIECES.

He also left the battery on his seat and it started SMOKING.  A flight attendant dunked it in water to get it to stop.

The pilots decided to divert the flight to an airport in Scotland, where Matthew was escorted off the plane and arrested.

He was in court this week and pleaded guilty to several charges, including disorderly conduct and making violent threats.  He'll be sentenced next month.