I was a member of AI for a long while, and sent off quite a lot of letters, but i got annoyed by the way the charity is going. It appears to be turning into 'human-rights lite', commenting on how terrible things are but doing little investigation of its own, and just trusting the fact that it is AI to get it some news coverage. I also became annoyed by this new 'womens rights' campaign; i have nothing against campaigning against domestic violence, sexual discrimination, etc, but at the end of the day i didn't join AI to blow a feminist horn (which is what this new campaign has turned into). One in ten men will suffer domestic violence too; but this is shrugged off as being 'unimportant'.
But i think the thing that finally did it for me was this commision they decided to send to the UK becuase our laws were 'worrying'; yes, there are some things this government does that i don't like, but that's what charities like Liberty are for- all AI seemed interested in doing was joining the 'kick the UK' bandwagon with little idea of why it should. I joined AI to add my voice to those who had none; not to add it to a mis-concieved publicity stunt.
Anyway, i have now transfered my membership to Human Rights Watch (which actually does some original invesigation now and then) and Liberty.