Our IT department forced me into removing Foxmarks (aka Xmarks) - a bookmark synching service, from my Firefox browser stating that 'it was sending sensitive data (read the companies' and its client's intranet URLs) from inside the company to an outside world which is a breach of data security & company policy.'
The convenience of accessing the same bookmarks when I worked from home didn't matter to them :(
Kind of ties in with the views some companies have about cloud computing...
Technically, Mordac may have a point here. Either you should be leveraging the power of the cloud or you're implementing end-to-end security (using cloud only to store).