I've never had anyone try to scam me (other than of course those shitty bots that anyone can see coming a mile away) because I'm too poor and too paranoid. I miss the first days of trading when prices were in flux and finding the right person could net you a lot of cool shit. I think I've mentioned before that I got a Bill's hat for a sandvich, and there was one guy who would open my crates up for me - I got so much paint from that. Once he even got an unusual from it, Purple Fetti Ze Goggles (yes they were "shit" but back then it didn't really matter, unusuals were fucking rare - people would stare in spawn if you had one). He let me borrow it for a day then asked if he could have it, and I of course agreed.
Eventually we stopped talking and I found out he got banned from one of our mutual servers for hacking (although he doesn't have a VAC, weird) - in the appeal thread he said his brother did it which I usually wouldn't believe but he was truly a great guy. He ain't been online in over 2,700 days. Hope he's doing well.
Hard to believe that was almost 8 years ago.