What you are doing not only violated Facebook's trademark (good luck calling it fair use), but it's also against Facebook's ToS. They have actively gone after extension authors who alter the Facebook experience and even deactivated their accounts. Rightly or wrongly, when you sign up to a service you are bound by the conditions they set out. In this case, making an extension to block advertising is probably not going…
I was never told what to do or how to change it so that my users would still recognize it. Also changing its name in "Cleaner - For Facebook" was suggested (and accepted) for the Safari extension by the Safari Gallery Team.
If I don't know what I'm doing wrong, I can't fix it. This is not about TM infringement, but the total lack of communication by Google.
Thing is that they basically told me I can't do anything if the original complainant gives his go-ahead ... after 3 months of canned responses.
(I'm the author of the post).