From the Toronto Star, a story about a retired minister who had her vanity license plates yanked by the Ontario Ministry of Transportation.
The plates read 'REV JO'.
An application to renew them was rejected because the 'REV' was deemed to imply that the ministry endorsed either or both of excessive driving speed or Christianity (or fast Christians perhaps?).
Apparently, the 'JO' was not considered offensive.
I can only hope that someone with the same diligence and highly attuned political correctness is monitoring the creation of vanity URIs.