First, a definition of the Dark Web (aka the Deep Web):

The deep web isn’t half as strange or sinister as it sounds. In computer-science speak, it refers to those portions of the web that, for whatever reason, have been invisible to conventional search engines such as Google.

Now, how big is it?

Make no mistake, the deep web is huge. Michael Bergman’s pioneering 2001 study, The Deep Web: Surfacing Hidden Value, estimated that it accounted for 7,500TB of data at a time when search engines could index only 19.

I can only imagine how big the Dark Web is today.

PandaWhale is useful for fishing good content out of the Dark Web.