Why are there no tools to find unused CLASSES?

Every now and then I work on larger projects where alot of cruft, in the form of unused Java files, has accumulated.  Each time, I unsuccessfully look through NB and its plugins for a tool that can find potentially unused java classes in a project.  I asked my Eclipse-toting colleagues and it, too, doesn't seem to have any such tool :-(  I always check the web for static analysis tools that might do the job - either my keyword searches are insufficient or there are just none to be found.

Does anyone know of such a tool?

I  am not looking for a perfect solution - I know that no tool would know whether statically unreferenced classes are dynamically referenced from somewhere.  I'm just looking for one that can check for static references.

Many thanks for any suggestions/pointers.
Tom

P.S. Eclipse and Netbeans both have "Find Usages" capabilities.  But with 3800 src files, I don't want to go through that exercise.