Big Brother is watching you

Ok this is scary.... a lady just knocked on my door and told me that I cannot keep my bike in my room. The thing is, how could she know? The reception was already closed when I came back with my bike, and I'm rather sure that noone else saw me in the elevator or elsewhere.
Then I remembered that it says "video surveillance" in the foyer.
In other words: They really seem to videotape all the time and actually look at those tapes closely. But then again, how do they know who I am? Face-scanners? Hidden cameras on every floor?
Switzerland is watching you...