Firefox uses 100% CPU when loading tabs

I was asleep and left my laptop on with Firefox running over night when the fan woke me up. My laptop sounded like it was going to explode. Then it shut down and the BIOS displayed a message saying my computer was shut down because it exceeded a certain temperature. Why is Firefox such a piece of shit?

>>3
Firefox sends all your data to Google anyway, where do you think they get your search suggestions from? In fact many Firefox features send data to Google because Firefox development is sponsored by Google.

Even https://developers.google.com/safe-browsing/ ships with Firefox so Google knows every page you visit. Privacy? lulwut