In all of the time I have lived and flown in Europe, I have seen one sign requesting volunteers (Continental Airlines in peak season August travel Madrid-Newark)

I was bumped involuntarily on an Iberia flight Frankfurt-Madrid. I was told that my luggage would not reach the plane since it was 45 minutes before take off?!?
When trying to approach the airline later, response was, "we got you back to Madrid, what are you complaining about now?" Flight left 4 hours later and no meal vouchers nor phone cards and God forbid had I asked for compensation!