I requested an Uber yesterday during a surge. The driver phoned me to ask where I was going. Upon my telling him, he said he'd see me shortly; but then immediately after hanging up cancelled the reservation. Presumably he felt that my trip wasn't worth his time.
This was particularly frustrating due to the time it took to get matched with a driver in the first place, and then the time it took to get matched with another (during a higher surge rate!). Furthermore, while the app makes it easy to complain about a trip you took, it is particularly challenging to complain in the situation I found myself in.
To Uber's credit, when I did manage to write them some feedback, they got back to me very promptly to say that they'd identified the driver and would be following this up