Lego Firefox by Johnath (cc by-sa)
... but a distressing number of our users wind up making some unwise choices and/or installing some dodgy third-party software that a guy on the corner said would be perfectly safe and legal and also a good time, and wake up with a headache and no wallet and some addons that don't _quite_ do what that guy on the corner said they would. And when they try to figure out why their computer is suddenly so slow, process monitor isn't going to tell them it's because that download-accelerator that ad on the torrent site said to install is mining bitcoins on the side, it's going to say "Firefox, 99% CPU".
Mozillian MeFite Mhoye adds insight and answers questions in Rhaomi's recent multi-link Crazy like a (Fire)Fox post.