I used to go into aol chatrooms for many years and people in chat could click on your name and on "send e-mail", since the screenname was also your e-mail address. Sometimes I would get dick pics from guys out of the blue, guys that I had never talked to before. They just sent out nudes of themselves and I always immediately deleted them and wished I had never opened them. I usually called the guys out on it in open chat too. Telling everybody that this guy just sent me his dick pics unrequested and that I thought he was rude, if not worse, for doing so- and it didn't matter how sexy the guy was!
I only ever want to recieve dick pics when I asked for them. I was exchanging "sexy" pics with one of my ex boyfriends, but after we had been dating for a while, cause he was often away for 1 or 2 weeks and then we'd exchange those pics and talk "sexy" on the phone or via text messages as well.
I have exchanged a few pics with guys before online that I had been chatting with for a while, and that I had been flirting with as well, but never with some random guy online.