Archive · 5 Aug 2026
TikTok Kept 15 Million US Users on Older Algorithm: Report
TikTok is an app that shows people short videos.
A special computer program, called an algorithm, picks which videos each person sees.
TikTok made a new, safer version of this program to show fewer videos that could be sad or scary.
But a news report says the company kept about 15 million people using the old version.
The company wanted to see how those people used the app compared to everyone else.
This is called a test, like trying two different recipes.
One teenager in the test group, Chase Nasca, saw videos about suicide and self-harm.
His family said those videos hurt him, and he died in 2022.
A court dismissed his family's lawsuit in 2025.
The report is based on a secret document that has not been checked or made public.
Many people are now asking companies to be more open about how they test safety changes.
Bloomberg reported that TikTok kept roughly 15 million US users—about 10 percent of its audience—on an older recommendation algorithm.
The decision reportedly came from a confidential internal 2021 document and was part of an A/B test with a control cohort.
The older algorithm was retained even though TikTok had developed a safer version intended to reduce exposure to harmful content.
One control-group user, 16-year-old Chase Nasca, died by suicide in February 2022; his parents' lawsuit was dismissed by the New York Supreme Court in April 2025.
The findings could intensify scrutiny of how platforms like Meta, YouTube and Snap test safety-related algorithm changes.
Bloomberg's reporting is not independently verified, and the internal document has not been made public.
- Who
- TikTok (owned by ByteDance), its US users, Bloomberg, and 16-year-old Chase Nasca, who was reportedly in the control group.
- What
- Bloomberg reported that TikTok kept around 15 million US users on an older recommendation algorithm despite having developed a safer alternative, using them as a control group in an A/B test.
- When
- The internal document and testing decision date to 2021; Chase Nasca died in February 2022 and his family's lawsuit was dismissed in April 2025.
- Where
- United States.
- Why
- The control cohort was reportedly retained so the company could compare whether the updated, safer algorithm affected user engagement.
Critics and Regulators
Tech Industry and Defenders
A/B Testing of Safety Features
Critics and Regulators
Keeping millions of users on a less protective algorithm without their knowledge raises serious ethical questions, and safety-related experiments need greater transparency.
Tech Industry and Defenders
A/B testing is a standard industry practice needed to measure whether a new algorithm affects engagement before broader rollout; the report does not establish intentional harm.
TikTok's Safety Record
Critics and Regulators
Allegedly delaying the safer algorithm suggests TikTok prioritized engagement over protecting young users from harmful content like self-harm videos.
Tech Industry and Defenders
Bloomberg's reporting is unverified, key details remain unknown, and TikTok has repeatedly said it is committed to improving user safety and reducing harmful content.
- Platform
- TikTok
- Owner
- ByteDance
- Affected users
- Around 15 million US users (~10% of US audience)
- Source
- Bloomberg report citing a confidential internal 2021 document
- Purpose of cohort
- Control group in an A/B test to compare user engagement
- Related case
- Chase Nasca lawsuit dismissed by New York Supreme Court, April 2025
- Verification status
- Not independently verified; document not made public