Unnecessary requests for information while traveling drive me mad. "Are you traveling for business or leisure?" is a favorite; unless it affects taxation (apparently the case in Berlin or a limited few other cities), it's none of the hotel's business.

The one that really, really got me was recently at the Delta Sky Club in Seattle; to take a shower, the operators of the spa asked me for my phone number. I protested strongly, and they insisted it was only so they could contact me if an item was lost or left behind. That seemed reasonable, so I acquiesced - only to receive text message spam with surveys and marketing information a few days later. I was furious at being lied to...