On line dating services protection
If you are a victim of blackmail or extortion, keep the evidence - take screenshots and save messages, the police may require it.
If you are a victim of dating fraud report it to Action Fraud.
For instance, Wikileaks Editor-in-Chief Julian Assange found his OKCupid profile made the internet rounds after it was discovered. Ross Ulbricht, aka Dread Pirate Roberts (founder of the notorious Silk Road Darknet market), also had a public OKCupid profile.
Furthermore, there are numerous online services dedicated to scouring the web for name matches.
How is the data you provide being used by the dating site?
Do they keep everything under lock and key, or is your information being bundled with thousands of other profiles, and sold to the highest bidder?