In a way, it is your individual choice, or so the marketing droids keep telling us, before sending us all the ads and all the spam to offer us some "choice". Nevertheless, a community will quickly recognize what is spam and what is not, without having to argue about it. Therefore, let us not waste time trying to define the obvious. The reaction is always the same: Aggravation and a waste of time. Which is why people try to fight spam.
See also: WhatIsaTroll
Ways to fight community spam:
Hardcore spammers often use automation: both to send large quantities of spam, and to bypass simplistic TuringTests that attempt to seperate computer-generated and human-generated content. Communities must be prepared to MeetForceWithForce.
The ways to fight spam are the follow the exact same structure that you use to fight any enemy that you cannot control. You can either be like a rock and try to build fences (HardSecurity), or you be like water and bend around the attacker (SoftSecurity).
When I was at MIT watching HowardRheingold talk about SmartMobs?, I met one half of the gestalt UseMod:AdamBraite. While Howard was talking about the problem of spam, the half of Adam Braite suggested that I knew the answer--as in SoftSecurity. I've been wondering what he meant, but maybe it's basically what's written above. -- SunirShah
That ignores the two realtime blackhole lists which were social for the most part.