[lusr]

I've been doing this for a while. I've caught out 3 companies selling (or leaking, presumably via an employee) my email address. In one case they claimed they'd do something and I never heard a followup (but received no further spam, which could mean the boss was in on it); in the second case the company never bothered replying (Topaz Labs, pretty disappointed with them) and I still receive spam directed towards the address; in the 3rd case I didn't bother doing anything because of the previous 2 experiences - I realised it didn't help much except in the extreme case of being spammed heavily, which so far hasn't actually happened.