In the past two weeks, Kamloops RCMP have been investigating at least four incidents in which thieves have drilled holes in gas tanks of trucks to empty them of the fuel. Kamloops gas thieves drilling holes in truck tanks to steal gas | Vancouver Sun
The Everett WA police department also warned about this several days ago: Everett Police warn of people using power tools to siphon gas from tanks | KOMO
The article says they're targeting trucks, most likely because they're easier to get under, and have large gas tanks. A Prius is pretty much the opposite of that, and probably not at much risk of having the tank drilled.
