Clearview AI has scraped over three billion photos from Facebook, YouTube, Twitter, Venmo and hundreds of other websites to create a facial recognition database now used by the FBI, the Department of Homeland Security and over 600 law enforcement agencies. Twitter just sent a cease-and-decease letter to the startup demanding that it stop taking photos and other data from its site and to delete any data it has already collected. Twitter accused Clearview AI of violating its policies.

The New York Times reports that, “Clearview’s database of photos dwarfs those previously used by law enforcement agencies” and notes that, “other technology companies capable of building such a tool, like Google, have decided not to because of concerns about the potential for abuse.”

In the wake of NYT’s breaking story about Clearview AI, Senator Edward Markey (D-Massachusetts) sent a letter to the company’s co-founder/chief executive Hoan Ton-That, stating that, “widespread use of your technology could facilitate dangerous behavior and could effectively destroy individuals’ ability to go about their daily lives anonymously.”

Among the 14 questions Markey asked Ton-That was for “a list of all law enforcement and intelligence agencies, as well as private entities, that use the app … [and] about the collection of children’s information by the company and how it vets its product for accuracy and security.” He demanded a response by February 12.

“In the absence of a rigorously enforced consumer privacy law, technology companies will continue to develop and market products that pose existential threats to our fundamental privacy rights,” stated Markey. Senator Ron Wyden (D-Oregon) also expressed concern, as did Josh Orton, an aide for Senator Bernie Sanders, who said Clearview’s practices were “disgusting.”

Facebook, whose policies forbid photo scraping said it is “reviewing the situation with Clearview … [and] will take appropriate action if we find they are violating our rules.”

NYT notes that, “it isn’t clear what power Twitter and other social media sites have to force Clearview to remove images from its database,” referring to a “a federal appeals court in California [that] ruled against LinkedIn in such a case, establishing a precedent that the scraping of public data most likely doesn’t violate the law.”

Stanford Internet Observatory director Alex Stamos, a former Facebook chief information security officer, stated that this case “eviscerated the legal argument that Facebook used to use on scammers and spammers.” Facebook would not confirm if it sent a cease-and-desist letter to Clearview; YouTube didn’t respond to a request to comment; and Venmo spokesperson Justin Higgs simply said that, “scraping Venmo is a violation of our terms of service and we actively work to limit and block activity that violates these policies.”

Clearview attorney Tor Ekeland confirmed he received the letters from Twitter and Markey and “will respond appropriately.” In an earlier interview, Ton-That “defended Clearview’s technology as a valuable resource for law enforcement,” adding the company will not release its app to the public “though some private companies use it.”