Blacklist a few more bots/crawlers.

Abonti hides what they are because they are "not ready", I'm not ready to
accept them.

A6 says hey don't crawl webpages, but then they scrape it, and they are an
"ads optimizer" service.

Diffbot fakes a referer of http://news.google.com/.

Meanpath is crawl-by-hire.

Openhose is too sketchy to tell what they want to be.

Plurk seem just spammers.

Proximic is another "ads optimizer"