There are also additional privacy setting all users can change, so that they can only get messages, or have users comment on their profiles, if they are "friends". This may involve a few fake "Friendship Requests" but it will certainly keep out the "love seekers".
We have beefed up the registration process, but we do realize that there are some relentless spammers out there that go through the whole process and are "real" people. What they look like, is anybody's guess, but they do tend to target Social sites.
Today, there were more of these that have been disabled and some of our members will have seen comments on their blogs from these "Russian Bride" types. Social sites, like this one, do have settings that all users are able to change to reduce (almost eliminate) this type of action, but then it's up to the users to pay careful attention to how they set up their "Privacy" settings.
While your profiles are visible to all and anyone that visits the site, you are able to change who can comment, on your blog entries, send you PM's etc.
Managing your privacy will certainly go a long way to reducing spammers.
Hope this helps.
Hans