So on this blog I maintain, I often see referrals from pages on which not only do I not see a link to the blog, but the page has nothing to do with anything that might lead someone to said blog.
For example, today, the blog has recorded 24 views (not necessarily unique visitors), but four of those were from a site that is selling shoes or something. The blog in question is about high school sports in Florida, and there's nothing on there about shoes. More importantly, when I visit the page, there is no link. This happens almost everyday, though not always this same page. One day a couple of weeks ago, I had a few referrals from a Web site that was in Arabic.
So what causes the referrals? Anyone have any idea? The best guess I can come up with is that whoever is maintaining those other sites has some mechanism for visiting other pages to appear in their referrals, drawing traffic to their own site. But even if that is the case, I don't understand how they do it.
It's nothing more than automated spam. We get it all the time on our referrals page (perhaps more so since we publicly display referrals) and I try to delete it as it comes in so you don't have to see it.
Not really any info on what exactly happened or what dangers resulted from it. People may want to change their passwords, just in case. I did. I agree with the sentiment here: This is unacceptable from one of the most-visited Web sites in the world.