pop-ups?

I don’t know about you, but a few days ago I saw something I hadn’t seen in a looong time: a pop-up! At first it scared me: “OMG Firefox can’t block pop-ups any more”, but it blocked all the others fine… a new kind of pop-up?
Today I found this solution on MozillaZine.org:

A lot of people have been reporting a new breed of pop-ups on the web.
This increasing menace is rooted in the pop-up capabilities of plug-ins
like flash and Java. If you’re seeing pop-ups and pop-unders, you’re
probably visiting sites that have flash or other plug-ins and those
plug-ins are being exploited by advertisers to abuse you with annoying
pop-ups and pop-unders.

Firefox has the capability to disable these pop-ups but it wasn’t
enabled by default in Firefox 1.0 because we had concerns about
websites that rely on plug-in triggered pop-ups for legitimate
functionality.

Give that these pop-ups and pop-unders have really started to spread
on the web, we’re testing a quick patch that enables the Firefox pref
to block them.

Read more here.
Download the Pop-ups Must Die! extension