Uber is having an increasingly tough time in Europe as authorities try to crack down on the tech-savvy taxi company.

Here's what's happening right now in London, Paris and Amsterdam:

London: The city's transport authorities are considering new rules that would create a lot more red tape for Uber, such as imposing a mandatory five-minute wait before passengers can start their journeys and barring the company from displaying driver availability on a map in its smartphone app.

London's transportation authority -- Transport for London -- said the new rules aim to improve passenger safety. But Uber has lashed out at the proposals and started a petition to encourage the authorities to ditch its plans.

"These rules make no sense," said Uber on its petition page. "We understand that [local] cab drivers are feeling the pressure from services like Uber. But the answer is to level the playing field by reducing today's burdensome ... regulations -- not to introduce rules that will be bad for riders, drivers and London."

Over 92,000 people had signed the petition within a number of hours.

Paris: Across the English channel, some of Uber's French executives were in a criminal court Wednesday, standing trial for six charges for allegedly running an illegal taxi service and violating data privacy laws.

The executives and the firm risk hefty fines as well as a prison sentence if they are convicted, but it will take months to reach a final ruling. The next hearing has been postponed until February 2016.

This is part of lengthy legal proceedings that have targeted uberPOP, an Uber service that is designed to help people share rides and carpool.

UberPOP operates in over a dozen cities across Europe and gives passengers a cheaper alternative to traditional taxis by letting private drivers offer rides. The fact that these drivers are not licensed doesn't sit well with established taxi firms and local officials.

In July, Uber suspended its uberPOP service in Paris to protect its drivers from violent attacks. The company said its drivers faced "intimidation, violent assaults, and organized ambush" during anti-Uber protests.

The courts previously tried to shut down the service at the beginning of the year.

Amsterdam: Authorities from the Dutch justice department searched an Uber office in Amsterdam on Tuesday and have confiscated some items as part of a criminal investigation into the company.

The department, along with the city's public prosecutor, say Uber is breaking transport rules when its uberPOP drivers present themselves as legitimate cabbies even though they don't have proper licensing.

The rule in question is currently under review and could be revised by the end of next year. The transport rules were drafted in 1998 and adopted in 2000, back when smartphones did not exist.

"We're looking forward to the Dutch government continuing the modernization of the regulations in order to encourage job creation and consumer choice," Uber said in a statement.

Dutch authorities have already imposed penalties on Uber worth 450,000 euros ($503,000).

Related: Uber's rivals are teaming up in Asia

Uber has faced a wave of regulatory and legal challenges around the world in the last year. It was temporarily blocked in Spain and had to tweak its services after a ban in Germany. It had also been suspended for a few weeks in New Delhi last year, after one of its drivers was accused of rape.

CNN's Pierre-Eliott Buet in Paris and Chris Liakos in London contributed to this report.