Their description:

"Information about your tabs is never transmitted.

...except with the 'share as a web page' feature.

...oh, and with Google."

Yeah I can totally see how "information about my tabs is never transmitted", because as we all know, sharing things with Google is as good as not sharing them at all.

Come on guys, Google will only know exactly which sites you visit. Not which specific file you're looking at. Don't be so picky.

What a load of absolute BS.