Google - Not as clever i ever thought?

“This site may harm your computer!”

I searched for w3csites and this was the first time i every notice that warning in Google’s search results.

I send Sean Ho, founder of the site, a short mail asking him about this warning. From his response:

First of all I would like to say that W3C Sites is safe to browse.

When I first got notified about the warning, I have followed Google’s instruction to review my website and found that it has been hacked to distributing badware. The badware was removed in just a few hours. Sean Ho in einer Mail

It seems like that there was badware or links to badware an the site and in that case Google`s warning would make sense.

Which makes me however thinking is that fact that Google is warning:

But that there are Google adds on the page

And the search is powered by google, too:

How does that match together?
Google is say “This page may harm”, but at the very same site you see adds by Google. In my opinion there are three different possibilities:

• The problem was not very seriously.
• The problem was seriously, but adds earn Google’s money, even on pages which may contain badware.
• The problem was seriously, but the database “warnings” is not connected with the “adds” one.

I guest: It´s probably the last option. Google’s department “adds” does not know which pages the other department “warnings” is indicating.

In that case, i can use all these Google services without any concerns about privacy.

If Google can’t connect and compare it’s very own data, how should the connect and compare all these millions of user data.