Uber is using a pattern of aggressive and questionable tactics in its effort to control the car-on-demand market, according to rivals. New data provided by Lyft, a competitor, shows that Uber employees have ordered and canceled more than 5,000 Lyft rides since last October. The data was provided to CNNMoney per a request made when reporting another story on the competition between the two companies. It's the taxi app version of ding-dong ditch. And it's not just a rogue employee or two: Lyft claims 177 Uber employees around the country have booked and canceled rides in that time frame. Bogus requests decrease Lyft drivers' availability, which could send users to Uber instead. But it's not just the company that suffers. Canceled rides jeopardize income that Lyft drivers depend on -- plus they spend time and gas money en route to passengers who have no intention of taking a ride.