I've seen it done for consultants before - in fact was working for mega financial services company in the years heading up to the 2008 crash. When it hit, they told all the consultants from the big consulting firms (i.e. Anderson etc) they needed to take a 50% cut if they wanted to stay on - almost all accepted the new rate.
Months later, when things continue to go really bad in the economy, they told them same firms, they needed to take another 50% cut (so now down 75%), most took that as well, but not all. Those that didn't take it largely found themselves unemployed for a very long time.
Just goes to show you how bloated those rates were to begin with.