First, it's already been unblocked.

Second, this is what it says at the above link:

--SNIP--

What happened when Google visited this site?

Of the 26 pages we tested on the site over the past 90 days, 4 page(s) resulted in malicious software being downloaded and installed without user consent. The last time Google visited this site was on 2014-04-05, and the last time suspicious content was found on this site was on 2014-04-05.

Malicious software is hosted on 1 domain(s), including zlubob.org/.

--SNIP--

They're doing a good thing with this, and they're helping webmasters who can't help themselves.