As the lead developer on a dating site myself, I can say that it's ridiculously hard to keep out spam profiles. We block by country, Project Honeypot entries, a

As the lead developer on a dating site myself, I can say that it's ridiculously hard to keep out spam profiles. We block by country, Project Honeypot entries, and HTTP header profiling, use captchas, and use other bot-sniffing tricks, but in the end we still have to manually ban IP addresses every day. We don't store passwords in plaintext though, sheesh. Edit: I just upgraded the hashing algorithm on the site from SHA1 to Bcrypt. Paranoia for the win.