Comment 13 for bug 162045

It is to store flash information files. I guess like cookies. They are probably harmless, but are not sanitisable in firefox. http://en.wikipedia.org/wiki/Local_Shared_Object

The problem affects windows as well.

On windows however, one can set options on the flash plugin to not store files, and these options are not available on the macromedia linux flash plugin.
http://kb.adobe.com/selfservice/viewContent.do?externalId=52697ee8&sliceId=1

There are bugs in mozilla -->
https://bugzilla.mozilla.org/show_bug.cgi?id=290456
https://bugzilla.mozilla.org/show_bug.cgi?id=400934
--