Art scammer on dA - https://www.deviantart.com/rolling999
Don't think it's worth making an entire thread for, but needs to be mentioned.
They commission artists for high amounts - I said $15-20 for mine, they offered $30, but asked for a sketch before payment. Tons of red flags, but on the off chance it was legit, I accepted. However, I only sketched the pose with no chara traits, and censored it liberally (it was a nsfw pose). I sent this to them and said I'd send an invoice if that looked alright. Though contact had been good up until that point, they read that note and stopped replying.
Looking on their userpage, they've gotten at least two others to fall for this, to give them sketches which they then refuse to pay for. PLEASE, to everyone out there, DO NOT EVER DO COMMS WITHOUT AT LEAST A DOWN PAYMENT!