Uber just got banned in Brazil's second-biggest city

5 stunning stats about Uber
5 stunning stats about Uber

Uber has hit another snag in its quest for world domination.

Rio de Janeiro's mayor has signed a bill into law that will fine drivers providing transport through informal taxis, including Uber. Other Brazilian cities, such as Sao Paulo, are pursuing similar bans.

In Rio, the city government plans to soon create its own app -- free to customers -- that will be mandatory for all taxi drivers and will include a function for people to submit complaints, reported state media.

The Rio ban deals yet another blow to Uber, the U.S.-based taxi-hailing app, which has run into plenty of problems at home and abroad. Taxi drivers in multiple countries have gone on strike, frustrated with what they say is a decrease in business. Regulators, meanwhile, have accused Uber drivers of operating without official licenses.

Uber called the Rio ban unconstitutional, stressing the "service provided by partner drivers is completely legal and backed by federal laws," according to a company statement.

In other markets, Uber is facing a different kind of roadblock: some of its rivals are banding together to slow its expansion.

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