I sent a packet to put in an item to sell for -2.147 billion mesos, then I logged into the level 200 to make a thread about it (they’re more trustworthy see, so they don’t know I’m a troll).
Anyway, you can’t normally put an item for a negative value. And the title of the sho pis self-explanatory.
In the end, it was just to see people’s reactions. It seems that some people have realized that it was a glitch.