After having a SourceForge account for about 10 years, I'm canceling it for one reason and one reason alone: Spam. SourceForge has this "feature" where anyone can email you at email@example.com, and they will happily forward it on to the email address you have on file with SF. That's great, except, I don't want spam bots emailing me. It would be great if you could either opt out of this behavior, or even specify a human-readable anti-spam address as the forwarding address, but SF doesn't offer either of these options. It's either you have an account and all the crap that comes with it, or you have nothing. So I choose nothing.
Thanks for nothing SourceForge.
So I guess if I actually want to use the SF site for forum activity, I'll have to re-create my account each time.
Update: Ok I lied, sort of. Turns out that if you delete your SF account, you can't come back and re-create it. This sucks because I like my persona, and should I come back, I'd like to re-use it. So now I'm willing to give feedback a chance. Vote for Solution 3!: SourceForge Spam Solution
Update 10/15/2009: You complained, and SF listened. I got a Tweet last week from @sourceforge informing me that they have added an option to allow you control over your alias behavior. You can find this setting at https://sourceforge.net/account/. Go there. Now! That is all.