I think impermanence would probably fall in the foolishness bucket. Those photos of doing shots out the beak of a pelican may be 5 years old; they'd still be used against someone. It's all a Google/Facebook search away now.

http://www.telegraph.co.uk/technology/facebook/6968320/Half-...

Edit: FB website integration comments aren't indexed by default, but FB does offer instructions on making them indexable.