I stock pile stock (no pun intended either), anything that can be used and I put them in folders based on the permissions set by the owner of said stock. I'm a bit odd like that..
I keep all the stock I use (or intend to use) archived and whenever I get a new hard drive, that archive gets uploaded to the new one, so it's entirely likely I've got stock that I acquired in 2005 somewhere in my collection.
Hmmm I suppose its possible, I notice I get hundreds of downloads of some of the material I upload. Though I often doubt they are by those that would ever use it for stock.
I keep all the stock I use (or intend to use) archived and whenever I get a new hard drive, that archive gets uploaded to the new one, so it's entirely likely I've got stock that I acquired in 2005 somewhere in my collection.