I just scrubbed the toilets with a toilet bowl cleaner that smells like a dirty toilet. Brilliant.
Seriously, the bathrooms smelled fine before. Now there are no bowl-rings, but the areas smell like poorly-maintained public restrooms. This smells like case of ammonia gone terribly wrong*.
P.S. The cleaning product is called "The Works". I cannot recommend it, unless you really love irony.
* UPDATE: It may smell like ammonia gone wrong, but it is actually hydrochloric acid, according to the MSDS (PDF). Thanks to canyonwren in comments for the clarification.