According to state regulators, car-pool services sold by ride-sharing companies including Uber and Lyft are illegal in California.

What the brew who is about is that services such as Uber, Lyft and Sidecar are allowing users to pickup additional riders to a destination and then split the fare. The California Public Utilities Commission is telling them that the new service violated state law.

The sent letter said that charging individual fares to passengers when multiple people are being transported in the same car is against the law.

Uber, which now operates in 45 countries across the world, expects regulatory challenges.