The stories of Americans calling police on people of color who are just going about their daily lives have gone viral multiple times, and prompted a national debate about everyday racism.

So one has to wonder what a Silicon Valley startup was thinking when it programmed its electric scooters to yell at people: "Unlock me to ride me, or I'll call the police."

A female voice from within Lime's e-scooters shouts the threat to anyone who tries to fiddle with the rides without downloading the app and paying. The company has also set their rides to blast cartoonish robot noises so loud that heads turn on busy city streets.

The threat immediately repeats on high volume and is the first and only sound the scooter makes. The words blare after less than a minute of a person standing on and exploring the buttons of the scooters, which Lime has been dumping on sidewalks throughout the US with little warning and without government approval.

There's no evidence that the obnoxious feature actually leads to an automated call to police. Asked about the Lime scooter's threatening message - which a Guardian reporter discovered while standing on one of the newly arrived scooters in Oakland - local officials in numerous cities expressed a range of disdain and confusion.

"Oh my God," said the Oakland councilmember Rebecca Kaplan after watching a video of a scooter screaming in a public plaza blocks from city hall. "Having a random voice yelling out, 'I'm going to call the police on you,' it's really scary."

Her city recently received national attention after a white woman called police on a group of African Americans barbecuing, one of many recent accounts to spark widespread outrage about racial profiling in the US.

"This is not only an annoying noise, this is a threat to people. For black people, that can really be experienced as a death threat," said Kaplan, who is crafting legislation to regulate the scooters and now plans to add a proposal to prohibit loud noises and threats.

"Why would they call the police? And could they call police?" said Nancy Kuhn, a spokeswoman with the city of Denver's public works agency, who said she had not heard anything about police threats from the scooters. Lime recently ignored Denver's orders to remove the dockless scooters from sidewalks. "That doesn't sound like a great idea to me ... Is this supposed to be funny?"

Aaron Peskin, a San Francisco supervisor, said it was no laughing matter for some of his constituents: "I've gotten plenty of complaints from residents and shopkeepers who are pissed off about the noise as well as the police state intimidation tactic. It's kind of ironic they go and plop them in the middle of the sidewalk, and then these things start abusing people."

Police spokespeople in Oakland and Berkeley - two northern California cities that have seen more scooters on the streets after neighboring San Francisco banned them - said their agencies had not heard anything about Lime's police messages. A San Jose police spokeswoman said she was unaware of any notifications the department receives from the company.

A police spokeswoman in San Francisco, where the scooters have become the latest flashpoint in the tech culture wars, said she was unsure if Lime had a system to "live" track potential crimes, adding: "You'll have to ask the company."

On Wednesday night, a Lime spokesman, Jack Song, said the company had "updated" its "anti-theft alarm" in a new model, which no longer has any message. The company was gradually phasing out the old versions, he said. The scooters, Song added, had not alerted police, but Lime had "worked with law enforcement on incidents of vandalism".

Repeatedly touching a scooter for 10 minutes in Oakland on Wednesday afternoon did not result in a response or call to police.

The threat, however, played on loop.