IMO Action should be taken against Google here, not the average user (about 70% of whom use Chrome).

Throttling based on user agent (Firefox, WebKit Safari, etc) would be a bad thing if you ran YouTube and wanted to encourage people to use Chrome - it would likewise be bad if you ran a website like HN.

Users have power when they have control - Google is taking that away, and that's why antitrust legislation makes sense. But users lose power when their choice of browser (in a market where there are only 2-3 choices) makes their web experience artificially worse.