so here's the deal:
one of my "bait sites" is visited by an EC2 IP every 2nd day, so it's quite obvious that it is an automatic mechanism behind it that fetches the front page of the site:
the address (54.215.88.152) is always the same, so it's safe to say it belongs to a single account, it's also not a simple bot because the page is fetched completely (a bot wouldn't load the actual images).
what is the most interesting is that every visit is lead by a search on yandex.ru:
ideas that spook around in my head in order to get behind that EC2 IP are JS, Flash, Teredo..