What is up with MLS referees not wearing badges? I have seen a few lately.
Here is an example:
you can see it as he issues a red card.
USSF answer (August 1, 2011):
The referees are supposed to wear the pro or the FIFA badge, as applicable. In this case the referee’s badge fell off during the first half and he and his crew were unable to find it. (Just goes to prove what we recommend to all referees: Carry a backup for every item in your kit.
We can only assume that the same thing happened to the other referees whom you saw.