If you feel that he/she is not honest, so answer for: "can u senme ur pic" is: "yes, bye" and turn hime/her off :-) You may feel strange to do that for the first time, but later you will realize that your time is too much valuable than spend it on those kind of "friends".

This might sounds strange reading it from a male, but this is happening not only on italki and not only to girls ;-)
I would like to have such widget like "I am studying <language>" with words "<italki.com>, not a dating site. Thanks for your understanding." and I think that it might be better to have those words "not a dating site" as a picture (like widget) because it seems many people are too lazy to read profile, but not so lazy to check a picture :)

I hate that kind of profiles like: sorry boys, I will not chat with you...
it sounds too much rude for me. Sometimes I just want to send message (when I see something interesting in his/her profile/answer/question.....) and not bothering with friend request but many of you have not enabled "Chat Now" or "Send Message", only "Add to Friends" which is really crazy combination...