The machine that I use at home is (a) fanless and (b) in a poorly-ventilated room which often exceeds 30 °C. So when websites use enormous flash ads, it’s not just annoying but can stress my CPU to the point of overheating, generating lots of irritating “running in modulated clock mode” messages in all of my open terminals.

Hurray then for Flashblock, a Firefox plugin to selectively block flash ads.