Doesn't sound good, but it has only been a day. I've never had any trouble on here, but the thieves can be cruisin here just like anywhere else. That said, I've had MANY of my listing pics from Gunbroker used on Armslist by thieves, so watch out big time on Armslist. When you see the pic out on the web, AND on Armslist, USUALLY the pic has been taken from a legit auction site like Gunbroker or one of the others, and is being used to run the scam on Armslist. There's no accountability there just like Craigslist. I've been alerted several times to this being done to my listings. Internet scamming is now rampant to the point the FBI doesn't even deal with it anymore until the scams reach the millions. The Armslist stuff doesn't qualify. Get a phone number or email involved and try and get a locale on it, then go to local law enforcement in that area. There's a BUNCH of shady dealing going on on there. I've bought things off there, but proceed with extreme caution. Every bad one I've backed away from so far has been unable to speak English well and generally rude or pushy or both, or doesn't want to talk on the phone at all. If anything on there makes you uneasy just back away from it.
ALSO, I'd report the username of the user on here to the forum moderators and administrators on here if you haven't already. They may be able to help.