A "war of terrorism on the streets of Chicago."

When politicians decide who gets to drive fare paying passengers, violence sometimes flares up, as it did in Chicago in the good old days;

Yellow was the more established operation, founded in 1915 by car salesman John Hertz (who later started the rental car business) when he realized he could turn unsold used cars into taxicabs. Prior to Hertz, the cab industry consisted mostly of independent owner-operators. Hertz--whose innovations included painting his taxis an eye-catching yellow and introducing a telephone dispatch system--leased the cabs to his drivers and ran a tight ship: Yellow drivers wore a uniform and polished shoes and were required to keep a whisk broom to tidy their cabs. Checker, run by Mike Sokol, was an association of independent drivers formed in 1919 by Oak Parker Frank Dilger. Drivers received insurance and a garage to work out of in exchange for paying an association fee. Hertz claimed that Checker was made up of men who couldn't get a job at Yellow, and rumor had it that one Checker garage kept a closet full of guns.

Tensions between the two companies had risen in late 1920 with the passage of the Cab Stand Permit Law, an ordinance that required drivers to obtain a permit before they could work the cabstands. Problem was, the Checker people said, only Yellow drivers were getting the permits. They believed the ordinance had been bullied through the City Council by Mayor William Hale "Big Bill" Thompson at the behest of John Hertz to drive Checker out of business.

So things degenerated into beatings and shootings;

[On the night of June 8, 1921]  the Chicago Tribune reported, a Yellow driver had been shot in the foot in Logan Square. A Checker driver had been arrested outside the Hotel Sherman for rear-ending a Yellow cab. Another Checker driver told the Chicago American he'd been surrounded by four Yellow cabs at 33rd and Michigan and had been driven into the curb. Still another claimed he'd been attacked by five Yellow cabbies and that the windows of his cab had been smashed.

Just before 1 AM, a black Stutz touring car approached the Yellow cabstand at Roosevelt and Kedzie from the south. ..... The Stutz's occupants opened fire on the cabstand, spraying the area with 25 bullets, one of which tore into Yellow cabdriver Thomas Skirven and killed him. Witnesses said the Stutz then sped north and disappeared. 

 Preview of things to come for Uber et al?