CainIV - 9:57 pm on Mar 28, 2012 (gmt 0)
FWIW I am seeing the following elements being potential issues right now
1. Blog networks / whois / ownership, and eval of template based websites with contextual outbound links that are not authority
2. OOP potential for sites with a lower number of inbound brand / company links and www links. This seems to be based on a number of factors including the specific vertical
3. The number of total questionable higher pagerank links - even if relevant - that some websites have pointing at them.
4. The total recent rate of link building.
Number four seems to be a flag that allows Google to instantly spot who is building aggressively, and then algorithmically eval those links, but difficult to say the exact system / approach.