You should always back your friends up, unless they do something really bad like murder or something, or make a pass at your recently ex girlfriend (a best mate of mine did that to me when I was 18, so I bought a bottle of beer, took it to the toilet, poured some out and filled the rest with wee and gave it to him), but it becomes a lot harder to support them when they do something insanely stupid.
A friend of mine got sacked from his job for putting a £600 gas bill on expenses. I mean, jesus. What did he think was going to happen? I have to see him on Friday and I might just avoid him all night so I don't unleash a torrent of "You're a fucking idiot" on him, because I don't know anything else to say.
Regale me with tales of your friends' stupidity