I don't know if it's a thing but most new xooglers wear their Google shirts to work within the first two weeks until they start getting FB swag. One girl even wore this weird looking hat with a fan on the top in Google colors.
Honestly, ex-MS folks are uber cool in my experience. They seem to appreciate all the crazy stupid over the top perks offered at FB - starting with world class food. Also ex-MS folks seem more disciplined and less spoiled brats. Xooglers are very annoying and always compare everything. "Our ice cream shop was better at Google". After about 8th comparison, I just wonder why they made the move.
“After about 8th comparison, I just wonder why” > ask them about their FB comp, initial grant and/or level. I guarantee one or more of it is a step up from their Google situation. If Google matched it they wouldn’t move to FB #fact 😉