Notes are applied to potentially misleading content by a bridging-based algorithm not based on majority rule, but instead agreement from users on different sides of the political spectrum.

As of November 2023, it had approximately 133,000 contributors; notes reportedly receive tens of millions of views per day, with its goal being to counter propaganda and misinformation.

[16] In November 2022, at the request of new owner Elon Musk, Birdwatch was rebranded to Community Notes, taking an open-source approach to deal with misinformation,[17] and expanded to Europe and countries outside of the US.

[27] In January 2025, Mark Zuckerberg announced that Meta will remove fact-checkers for Facebook, Instagram, and Threads, replacing them with a community-orientated system, similar to Community Notes.

The bridging-based machine-learning algorithm requires ratings from both sides of the spectrum in order to publish notes, that can have the intended effect of decreasing interaction with such content.

[36][38] Since 2023, Community Notes are often attached to shared articles missing context, misleading advertisements or political tweets with false arguments,[19] from content receiving widespread attention.

[40] Notes have appeared on posts by government accounts and various politicians: the White House,[41][40] the Federal Bureau of Investigation,[42] and U.S. President Joe Biden;[43] UK Prime Ministers Rishi Sunak[44] and Liz Truss;[45] former U.S. speakers of the House[46] and presidential candidates Ron DeSantis and Vivek Ramaswamy;[47] U.S. representatives,[48] senators,[49][50] and Australian ministers;[51] as well as X owner Elon Musk multiple times,[41][49][5][52] that in February 2024 led to Musk arguing with the program.

[5] In July 2024, as part of a pilot program, X announced the ability for eligible users to request Community Notes for certain posts, that would be directed to "Top Writers" of the software.

[55] Former head of Twitter's Trust and Safety, Yoel Roth, has since expressed concern over the effectiveness of the system in the early stages of the program, stating that Birdwatch was never supposed to replace the curation team, but instead intended to complement it.

In April 2022, a study presented by MIT researchers subsequently found users overwhelmingly prioritised political content, even though 80% were correctly considered misleading.

[26] Regarding the situation in Israel and Gaza, with the difficulty of identifying accurate information and the number of unknown factors, MIT professor David Rand said "what I expect the crowd to produce is a lot of noise", regarding the crowd-sourced system.

A contributor otherwise described that the system is "not really scalable for the amount of media that's being consumed or posted in any given day", while X states that the program is having a "significant impact on tackling disinformation on the platform".

"[57] The fact-checking website Snopes discovered three posts from verified users, who had shared a video of a hospitalized man from Gaza with false captions claiming it showed "crisis actors", had failed to receive any Community Notes after 24 hours.

[31] Wired has documented that Community Notes is susceptible to disinformation, after a graphic Hamas video shared by Donald Trump Jr. was falsely flagged as being a year old, but was instead found to be part of the recent conflict.

[9] In November 2023, the Atlantic Council conducted an interactive study of Community Notes highlighting how the system operated slowly and inconsistently regarding Israel and Gaza misinformation.

[1] In May 2024, John W. Ayers, a behavioural scientist from the University of California, San Diego, published a study in the Journal of the American Medical Association based on fact-checking of COVID-19 vaccines.

[2] A 2025 examination of Community Notes’ design, use, and outcomes, suggests that the system is built around an "outdated and extremely narrow understanding of disinformation".

Researchers found that Community Notes volunteers rarely addressed the context of 'satirical' content, ignoring the potential for benefits or harms, and the complexity of disinformation.