[quackerhacker]

This may come off as jokative, but the people that are tricked could always ask for a picture of the person with a newspaper or a love note for proof that they are talking to the actual person, and not just some impersonator.

Personally, I can't get past the fact of falling for someone online. Just today I met one of my online professors and it was awkward, yet online we're both very chatty.