Would a Boycott browser plugin work?

Just a small idea I've had, and can't find anything similar except for specific boycotts.

A browser plugin that:

- Users submit boycotts (eg "Evil Corp Boycott" which has 100 websites listed) - Browser plugin users sign up to boycotts - Anytime you browse a website in one of the boycott lists it asks you if you want to continue, or visit an alternative page - Could even extend cleverly into product listings (EG "Evil Chocolate Corp" products on Amazon are obscured)

Boycott as a service if you will! If users wish to go to an alternative, perhaps there's some referral bonus you can get to monetise the plugin.

Boycotts never seem to be effective as it takes education, conscious effort and meaningful numbers. If this sort of plugin got enough reach I think it solves a lot of those issues.