Yeah I can personally vouch that Sumskillls (three l's) is an impostor along with the marco649 guy, he didn't scam me though.
I actually had a chat with him on steam trying to sell my Dota 2 invites. He kept insisting me to hurry and said he had to go somewhere and what not and come on, really? That is the first sign of a scammer right there and then is if they are rushing you for some god awful reason. I could see it a mile away but I still played along. He kept trying to make me trade first even though that is the dumbest thing I have ever heard. Someone who just joined yesterday and has no vouches, no credibility and no experience expects me, a guy who has been here since November of last year and has previous vouches wants me to trade first? Get real. It is also funny how this guy links his "vouches" to the real person he is trying to impostor. I mean I am not stupid, I can see the difference in join date and the difference in posts and even notice that his grammar is terrible compared to the original Sumskills, Masiif, Marco649 ect. It just made me chuckle at the end of the day.