Well, when guests put the "do not disturb" sign on the door, hotels should respect their wishes, right? If I put that sign on the door and then find out that my room was entered nevertheless, I would also think really hard before booking a room at that hotel (chain) again, not because I had something to hide, but out of principle. Also, what are they hoping to find? An unlocked laptop with some kind of hacking software running? I don't think hackers worth their salt would be so naive (except maybe if they leave the laptop there as a "honeypot")?