I personally verify a member's profile, even if photos seem pretty real, and his/her description. I have a mod from AntonLV which can ban access from certain countries, but i don't rely on it 100% but let's say 60%. Anyways, before i activate their profile, i am checking his IP and it's IP history on ripe and google, if the specified IP has been previously reported in dealing/involved with spam/fraud etc. It turned out to be pretty effective... Not mentioning that i have a BIG announcement for my see more members after they're logging in, explaining all the possible scam scenarios. I'm not saying i love this job, but is just a substitute until i find a better solution to fight those pricks. Hope it helps some of you guys...
And adding IPs to blacklist i can say is useless, because nowadays people have dynamic IPs, and banning their entire IP class will definitely lock access to innocent ones. So its a dilemma. Think twice