Perhaps try an addons for your browser.
I'm on chrome and i've "ghostery", surely it must have the similar for firefox.
Ghostery stop trackers...etc...
i've noticed that also (checked browser) and read this post.
till now i've desactived on zonegfx but now it's ON
I hope that it will be enough to stop it
(when is added, and you are on a page (website) left clic on the mouse on the blue ghost (and choose to restric, limit)