Question about community toolbar security

Hi everyone!

I have created a community toolbar for a facebook mafia wars clan. We always use the toolbar while on facebook and especially when gaming. My problem is this. We have a lot of members who join the clan and some who leave, so I thought it was a good idea to secure the toolbar's download link in the clan's forum. That way, anyone who has access to our forum he will be able to use the toolbar too. The problem is anyone can store the link to a notepad in his computer so I'd like to ask if it is possible to link the toolbar's link with my forum's link somehow in order to secure my toolbar. I have no such knowledge that's why it's been a problem doing it on my own.
I hope I was clear enough, I mean I don't even know if what I'm asking is even possible!

I appreciate your help

Yes, but then the link can anyways be stored when its added to a html page of a forum.

so, it's useless. I thought if a member left the clan he would lost permissions to the forum and at the same time he'd lost any rights to the toolbar. Anyway, thank you for the wuick response. I might try something else then