I just had the most disturbing experience at Goodreads, which I have linked to Facebook.
Every time I load the page to write my review, an ad attacking the Democratic candidate for Congress in my district pops up on the page. It opens if you "rollover" it and when you close it, it doesn't stay closed. Very disturbing. I can't even 'save' my review because it covers that area of the page.
I thought robo calls were annoying but this beats anything I have seen. Scary.