[2][3] The legislation set guides on child online safety, notably banning companies from knowingly collecting the data for anyone under 13 without parental consent.

The bill was a direct result after Frances Haugen, a data scientist for Facebook, leaked internal files through The Wall Street Journal in 2021 that showed negative effects of Instagram on minors' mental health, among other topics.

The leak led to a Congressional investigation of Big Tech's lack of protection for young users with Instagram CEO Adam Mosseri testifying to Congress in December 2021.

[9] President Joe Biden pushed Congress to pass legislation to protect children online during his 2023 State of the Union Address, leading Blackburn and Blumenthal to reintroduce KOSA in the Senate on May 2, 2023.

[12] In November 2023, whistleblower and former Meta engineering director Arturo Beja testified in congress before a Senate subcommittee hearing about social media and the teen mental health crisis, leading to a renewed push for the bill.

[26] In August 2024, Punchbowl News reported that the Republican leadership of the House would not advance KOSA, citing a staffer who referred to "concerns across our Conference".

[30] The Kids Online Safety Act, if signed into law, would require Internet service platforms to take measures to reduce online dangers for these users via a "duty of care" provision, requiring Internet service platforms to comply by reducing and preventing harmful practices towards minors, including bullying and violence, content "promoting" suicide, eating disorders, or substance abuse, sexual exploitation, and advertisements for illegal products such as drugs, tobacco, or alcohol.

[46] They have criticized the bill for being "too vague" in what it defines as "harmful content" and for potentially expanding the power of the FTC,[47] many have argued that the bill could be used to target marginalized communities (mainly the LGBTQ community),[48] censor free speech protected by the 1st Amendment,[49] make it harder for minors to search up information on controversial topics like racism, climate change, and LGBTQ issues, and implement ID-based age verification systems.

[57] Republican Senator Rand Paul, who once called it "a Trojan horse",[47] argues that KOSA would be a "Pandora’s box of unintended consequences"[58] due to vague and broad provisions that would allow "nearly limitless content regulation" because platforms would "censor users rather than risk liability".

[67] EFF columnist Jason Kelly states that in the framework provided by the bill, that KOSA could be used to censor education about racism in schools since it could be claimed that it impacts mental health.

A group of 100 parents of trans kids signed an open letter shortly after the comments telling members of congress to oppose KOSA.

[69] To address these concerns, the bill's language was altered so that the "duty of care" only focused on the product design features that influenced minors' behavior with the platforms, and not the content.

[81][82][83] A similar law to KOSA was vetoed in Vermont by Governor Phil Scott, with his reasoning being that it would likely harm small businesses, violate the First Amendment, and die in court.