Oh no she didn't!!!!!! What a B!?

They do this where I work, too. We have two desks, and they are manned 24 hours a day. It's actually common for the next person, before they sit down, to change chairs (no one wants a hot seat) wipe down the keyboards, phone, etc, with a disinfectant. When I first started working there, I was a little offended. But, then I realized that it actually does cut down on the germs and the stickiness (some people eat at the desk), so I don't let it bother me. Just be glad your working next to a clean person, you could have a coworker like I used to sit next to. She'd leave a ring of food crumbs all over the desk, there was sweet and sour sauce encrusted on the phone, and she sweated so much, the chair would be damp. Anyway, its actually a common practice among people who share an area or sit at a place where others have access. I wouldn't take it personal.