A fatal flaw uncovered yesterday by a Mozilla-friendly chap - and who knows when by naughty scum-of-the-earth hackers - can only "expose the contents of every file on your local hard drive to every site you visit", reads a posting on Mozilla's Greasemonkey site.
To make matters worse it's quite a simple matter to grab all your info, data, porn collection or whatever and send it all "anywhere it the world".
Users of Greasemonkey of any flavour should stop using it. In fact, they should unintall, disable, burn, purge or trample on any versions they may have anywhere on any machine hooked up to the wibblesome web.
A fix should be on the way. In the meantime, steer clear, is the advice. ยต
Update
The only safe Greasemonkey, we hear, is version 0.3.5 which is "neutered" and available from the greaseblog page
below.