Shaco boxes and sweeping lens

Okay, so if I have a fully stealthed and ready to activate Jack in the Box on the ground, somebody can use a sweeper on it, and walk up and auto attack it and kill it without it going off. I understand them being able to see and attack it, but when they get within its range it should still fear them, right? Is this intended? Also I don't know why the boxes are vulnerable to aoe. Just putting that out there but in a teamfight they are virtually useless to throw down mid fight because some stray aoe always takes them out. They should have to be targeted and auto attacked imo.