After a big drop of  google search traffic in the last week, only now i can see how important is the google.
Hey goog we don`t need the prof to see  who is the real monopolist.
Google advices are:
Read the guidelines carefully and there should be no problems.
Some of my sites lost the 70 % of  search queries from google  and it keeps falling,  i have done nothing suspicious, nor i know what could be the problem.

I searched a lot on this problem and i even tried to see if this happened to anybody else.
Google trends shows some interesting information on domains you type, i did this:
najdi.si, 24ur.com, rtvslo.si, siol.net
You may try your own domains or competitors to see the traffic trends,  and all i see is the drops, no boosts.

I have no solution and i am hoping like the others, that google will eventually bring back my sites to its position where has it been before.
Here are forum threads on this topic:

I have lost my rankings, Google has dropped me
Google Traffic drop – Sandbox
Google Page level penalty for comment spam – rankings and traffic drop
Possible Causes Of A Websites Traffic Drop
Anyone having huge Google traffic drop