Is it a cab, a car or just a nuisance?

When is a taxi not a taxi?

A question that's been playing on the minds of officials in the Belgian capital, Brussels.

An American firm recently launched its smartphone app in the city, allowing ordinary drivers to share their car with a stranger, for a small amount of money.

UberPop, as it's called, is cheaper than taking a cab, and so has proven popular with Belgians.

But not with taxi drivers.

So the local authority has banned it.

Many customers of the service are unhappy.

Luigi Marocco, the head of Brussels cab firm, Taxis Bleues, says the UberPop drivers have got an unfair advantage.

The Brussels authority has sided with taxi drivers like Luigi Marocco, and banned UberPop.

The man in charge of the app in Brussels, Pierre-Dimitri Gore-Coty, is understandably disappointed.

Brussels is also known as the capital of the European Union. The continent-wide authrority based there has weighed in on the issue too.

Ryan Heath is a spokesman for the European Commission -- I asked him about new technology disrupting traditional jobs