Indian cafe chain customers upset by use of facial recognition to bill them

London(CNN Business) An Indian cafe chain popular for its chai drinks is under fire for using facial recognition software to bill its customers, with some taking to social media to express their anger at what they say is a loss of privacy.

Nikhil Pahwa, an internet activist and founder of Indian media watchdog MediaNama, criticized cafe chain Chaayos by tweeting a video on Wednesday apparently showing the facial recognition system in a store in Delhi.

Pahwa told CNN on Friday: "The scan began on its own. I had to tell the cashier I'm not interested in this and he switched to a screen that asked for a phone number input. I declined that too."

Pahwa said he worries about the risks of companies like Chaayos having this data, which in his view has been collected without "proper consent."

He added: "Systems like this that collect such personal and sensitive data, it normalizes it and I'm really worried about that normalization."

Since Pahwa's tweet, other social media users have shared their concerns about the chain's collection of facial recognition data.

In a Facebook post on Thursday responding to the criticism, Chaayos said it started its facial recognition feature recently to "reduce the overall customer purchase time," and stressed it was still in the testing stage.

In the statement, Chaayos said it was "extremely conscious" of its customers' data security, encrypting the data and not sharing it with third parties. It further added that customers can opt out of the process.

However, on its website, the terms and conditions of the chain's loyalty program state that customers "should not expect ... personal information should always remain private."

Chaayos has not yet responded to CNN's request for comment.