R-E-S-P-E-C-T

Once upon a time, in a land far, far away....(Okay, on Friday in the 4th floor of Menk Hall in Stu East), the unexplainable happened. I went into the bathroom, and when I went to the sink, I noticed a lanyard, key, and ID holder on a shelf by the sinks. I was the only one in there, so I went to see who it belonged to. I went to look in the ID holder, and the ID was gone. I thought that was really strange, then I thought for a second and thought, "this lanyard looks a lot like my roommate's..." and compared the key. The key looked exactly like mine, so I went back to my room and asked my roommate if she had her lanyard/ID. She said she didn't, so we went back to the bathroom and we got her key. She then started to naturally freak out because her ID wasn't there, and we practically tore the bathroom apart looking for it. We then came back to the room to look for it again. Still no sign of her ID. We then tried asking our RA and went to the front desk, but no one had it. We later talked to another girl on our floor and she said she saw the ID out of the ID holder about 20 minutes before I did, but she thought my roommate was in the bathroom so she didn't bring it to her. In the twenty minute time span, someone stole her ID. Because this was a Friday night, she is unable to get another ID until Monday. In the meantime, I am letting her in the building and the bathroom, and she is getting food by using her ID number.
What I would like to know is: Why would someone want to steal someone else's ID? We're on an honors overflow floor. I would think that these people would be more respectful towards other people's belongings...but I'm starting to REALLY not like the people on this floor.