Meeting up with people you met on the internet for the purposes of selling things should come with certain precautions, and going into a real-world sale prepared and with your brain turned on is important.
A seller posted his vehicle online, and agreed to meet a potential buyer at a hotel parking lot. The supposed buyer had some friends with him, and they absolutely weren’t there to make a purchase.
One of the guys jumps in the back of the seller’s car, while the other tries getting in as well. The suspect in the back seat points a gun at the driver and tells him that a robbery is happening. The driver floors it, but quickly stops once threatened again by the suspect.
They got off with some of his possessions, and luckily this guy got away unharmed.
Understand that if you meet people from the internet, that you should be doing so in a safe place with people around. Many police stations offer locations on their premises to do these types of transactions, with eyes always watching.