[smoldesu]

If you licensed your codebase under GPL, you could demand they publish the modifications to embarrass and discredit them. Otherwise, you likely don't have many options besides complaining to Google and seeing if they agree to take the copycat down.

[orderedtree]

I just arbitrarily chose MIT :(. I'll make sure to use GPL next time

[smoldesu]

Make sure to consider the consequences of all the licenses. I choose GPL because I like what it stands for, but MIT can be the right tool for the right job.

IANAL, take my advice with a grain of salt.

[brucethemoose2]

Yeah...

I am a MIT/Apache person, but GPL is a good license for a Chrome extension.