Starting Thursday, air travelers will have to leave their lighters at home. Unlike guns, knives and other dangerous items that a passenger cannot carry aboard but may stow in checked bags, lighters are banned everywhere on a plane.
[...]
Lighters haven't been permitted in checked bags for at least 30 years because they might start fires in cargo holds. Congress passed a bill last year adding lighters to the list of items prohibited in the cabin.

The genesis for the ban was Richard Reid, who tried unsuccessfully to light explosives hidden in his shoes on a trans-Atlantic flight in 2001. He used matches.

Cigarette Lighters Banned From Airplanes [news.yahoo.com / ap]
via germany doesn't suck - or does it

streichölzer sind aber noch immer erlaubt, allerdings mit enschränkungen (u.a. nicht mehr als vier streichholzbriefchen) und dreieinhalb jahre nach dem 11. september 2001 wird diese regelung nun durchgesetzt. naja...