A somewhat brief article as unfortunately I have not left myself enough time to write a proper commentary on the subject: Microstock contributors are probably already aware of the thread at microstock group and 'movement' organized by boycottfotolia.org
The issue stems from photographer sentiment that devaluing of their work by Fotolias launch of 'dollar photo club' is something of a 'last straw' considering the license terms, image resolution etc provided. I can't really say I blame them considering Fotolias track record on transparency (or lack thereof).
Fotolia have now provided an opt-out from syndication of your Fotolia port on dollar photo club, 'DPC'. The option can be found by editing your profile on Fotolia and selecting the "contributor parameters" tab, there is a modify link next to "Sell my files on DPC".
I think that today (May 1st) should be a day for sending a signal of a mass opt-out rather than deleting portfolio or images. I know that opinion may undermine the pledge that some contributors made on the boycottfotolia site but I feel a middle ground has been reached (ideally it would be an opt-in). Overall it's up to each contributor to read all the information and make their own decisions where and where-not to sell.