Good point Smeagin, but again it easy to get info about changes but are they using it in the algorithm.
Who doesn't break the rules?
Webmaster Guidelines
I am sure the rules on linking change daily. They are now saying:
Excessive reciprocal links or excessive link exchanging ("Link to me and I'll link to you.")
What is excessive? 1 no, 2, no, 200 dunno
I am sure that is new.