The algorithm-based recommendation system, developed by Google, has surprised users with strange anomalies on multiple occasions, but the corporation has never really revealed how this keeps happening.

Numerous YouTube users have recently been seeing a two-hour newscast from CNN on the day of the 9/11 attacks in their recommendations, despite the fact that they had not searched for similar videos, the website Motherboard reported. A specific video, uploaded five years ago, has recently received thousands of comments from people wondering why the video service had decided to recommend the footage of the horrible terror attack to them.

It's unclear, what triggered the strange recommendation, with a Google spokesperson refusing to state the reason behind the incident to Motherboard, only noting that it was not related to a glitch that happened two weeks ago.

The recent YouTube recommendation glitch also showed users content that they were not interested in. One Reddit user said that he had been "bombarded" by videos about the videogames Team Fortress 2 and Undertale, while he had only searched for Splatoon and Mario related content. A YouTube representative responded to questions on Reddit, saying that the company was aware of the glitch and would be fixing it shortly.

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Motherboard suggested that currently, the popularity of the 9/11 video is "self-sustained" by users who are seeing it in their recommended lists and then open it out of curiosity as to how it got there. Google has previously faced problems with users intentionally creating anomalies in the search engine results. At one point, internet users had allegedly caused the search engine to bring up US President Donald Trump in search results for the keyword "idiot".