The controversial way to earn $6,600-a-month in 'free' money from bike share scheme

Hustlers have found a way to make thousands of dollars a month moving bicycles in New York City .

Citi Bike - a bike-sharing program operated by Lyft - is the largest of its kind in the country with 25,000 bikes and over 1,500 stations across Manhattan, Brooklyn, Queens, the Bronx, Jersey City and Hoboken.

To keep up with demand, the company is paying people looking to make quick buck to move Citi Bikes from full docking stations to empty ones.

The program called Bike Angels was created in 2016 and encourages riders to move bicycles in exchange for points that could be used for rewards like merchandise, membership discounts and gift cards.

Now people have found a way to maximize the system by monitoring the app and moving bikes from one docking station to another a few blocks away to create a need for their services - then getting paid up to $6,000 a month to ride them a short distance back.

'We imagined people would do it as a recreational fitness kind of thing. We never imagined anyone getting really obsessed,' David B. Shmoys, a data scientist at Cornell University who helped create the rebalancing algorithm, told The New York Times .

Bike Angels noticed that the algorithm awards points on a sliding scale based on need.

Removing a bike from a completely full station earns up to four points and docking at an empty station earns up to another four.

People who move at least four bikes in a 24-hour period get all their points multiplied by a factor of three, according to The New York Times .

Lyft pays 20 cents per point and each ride can create a maximum of 24 points - ideally a person could can earn as much as $4.80 for a single ride.

Some Bike Angels found if they work together to flip the stations they can maximize their profit.

'This is one of my side hustles. I'm probably a vulture in some people's eyes. And I guess that's fair,' Bike Angel Mark Epperson said.

The company tracks its top performing Bike Angels on a leaderboard and the current leader had amassed 19,394 points by September 18 - equal to $3,800.

In July, a Reddit poster called out the scheming Bike Angels criticizing them for abusing the system and hogging bikes to make money instead of letting users take them.

'Seeing these people in action is super frustrating as a long time member of the Bike Angel community. People like this should have their memberships revoked,' the person wrote.

Flippers told The Times Lyft tolerate their antics for years but in August they received a warning about their behavior.

'It appears many of your points were earned by engaging in station flipping,' the letter read in part.

'Continued instances of station flipping could result in removal from the Bike Angels program.'