If you have been having trouble with your Google search, this may be why, below is an email sent out from our network administrator.
An issue has developed with the recent release of Firefox 28. You may
have encountered this already. Something in the update conflicts with Safe
Search, affecting Google especially. Safe Search is enabled on our web filter,
and it removes "inappropriate" content from search results. This is based on
what the search engine deems inappropriate. You essentially cannot search
through Google.
I've encountered this on my own Windows desktop, and several users on
campus, both Mac and Windows. In my case, I've rolled back to the previous
version, 27.0.1. First, I backed up my bookmarks, and then completely
uninstalled Firefox. I downloaded an older version from here.