The way of the web has become very social, as you are more than likely aware. Fortunately, this makes for more widespread conversations about any and all issues that are deemed worthy of discussion by anyone on the Internet.
Unfortunately, it also opens up many pathways for abuse including spam, which can quickly turn a positive user experience into an ugly one.
As the web continues to become a more social animal, more and more webmasters find ways to make their own sites more social. Essentially, this makes for a web full of little social networks. A webmaster that is going this route may run into some of those spam issues right in the profile pages of his/her so-called users.
Jason Morrison of Google's Search Quality Team has posted an interesting article on the company's Webmaster Central Blog. Within this article are 8 tips for dealing with this social profile spam.
The tips are:
1. Make sure you have standard security features in place
2. Use a blacklist to prevent repetitive spamming attempts
3. Watch out for cross-site scripting (XSS) vulnerabilities
4. Consider nofollowing the links on untrusted user profile pages
5. Consider noindexing profile pages
6. Add a "report spam" feature to user profiles and friend invitations
7. Monitor your site for spammy pages
8. Watch for spikes in traffic from suspicious queries
Morrison elaborates on each of these, but I think you get the gist of it. "Google is constantly under attack by spammers trying to create fake accounts and generate spam profiles on our sites, and despite all of our efforts some have managed to slip through," he says, citing the tips as ways to make spammers' lives more difficult.
It would appear that spam (in any form) just isn't going to go away. All you can do is use the tools and strategies that are at your disposal to minimize it and try to maintain a positive user experience. That's what Google does.