-snip-
The only true protection against such people is to keep your common sense. These kind of trolling/impersonation is so awkward I really don't think anyone with more than 80 IQ will be fooled. And if you got caught it is your own fault.
These scammers can be tricky sometimes, do not ever think you are smarter then them. Be allways carefull, even when you think you are dealing with someone you know. And allways listen to your gut, if it feels phishy, just say no. I have done plenty of trades via steam and only one legit customer was repeled because I was to carefull.