Netbooster, Absolute Référencement, CVFM, Ability Référencement and 1ere Position have see their sites ban from the Google index. Thoses players, like the number one in Europe, Netbooster also been out of Yahoo.
Some of the customers of thoses agencies also get penalized. It will make a huge backlash in the SEO community in Europe.
The reasons I suspect for thoses penalities is huge quantity of doorway keywords overstuff pages generated dynamically by script to reproduce the uncrawlable database of theirs clients and huge cross-linking strategies!
When I discuss of thoses strategies on french forums and with a manager of one those company more than a year ago, they always tell me: It is impossible to do other way, they don't want to change the backend of the site nor to use Url rewriting because "blablabla" and security and "blablabla". My response was always : Tell the customer to call you *before* his next makeover and let them use costly PPC campaign instead!
May be now they will start to educate web agency to stop making uncrawlable site at the place of using bypassing way to get on the SE index.
Via Zdnet France (in french)