There was an old account named Lua50. It's rumored that if you visit its profile, you will be its next victim. Once you play a game after visiting his profile, weird things start to happen, like your stats get wiped, your default animations are swapped, and your game eventually shuts down. If you play another game, same things occur, except lua50 joins the game.
It is rumored once a month, a hat appears in the catalog named "Lua". Anyone who bought it would either vanish from ROBLOX, become sick the next day or have their memory of ROBLOX wiped.
If it joins your game, and you aren't already cursed, your computer breaks regardless of what type. Some players report their routers shutting down, or a note on their computer saying "Gotcha!"
lua50's account is deep in the ROBLOX database - you must use TOR to fully access his profile. When you try to visit it without TOR, it will show that the account does not exist.