In Germany? Not saying that it doesn't happen, but it is illegal. (Which often is an important argument to why Taxis are protected against competition, since they are forced to provide services that are not always profitable)
Uber just launched in Romania and it's having a hard time getting off the ground. I asked a taxi driver why he wouldn't join. He said he'd be scared for his safety from other taxi drivers.
Anecdotally, getting a cab from a major hub (airport, train or bus station) in Bucharest, without calling dispatch, entails a fixed price and the meter turned off. Illegal? Surely.
The main advantage of western countries, culminating in the U.S., is that laws are enforced regularly and predictably, most of the time.
Germany is doing just that. They're old laws, sure, but they must be enforced until they get a change to revise them.