Seems to me any thief would steal the feeder and dump out the corn to make the feeder lighter during the theft. That is, unless it is someone you know who doesn't want to get caught.

I know fora fact that bears can empty a feeder in no time at all if they can get to the legs and bump it repeatedly, making corn spill off the feeder tray to be replaced by gravity with more corn that gets spilled off, etc. etc. etc.