Several stream-ripping sites have been unable to download and convert files from YouTube starting a few hours ago. It appears that the video streaming platform is actively blocking requests from these sites. While the reason for the sudden blocking efforts is unknown, the music industry would certainly welcome a more aggressive stance from YouTube.

Free music is easy to find nowadays. Just head over to YouTube and you can find millions of tracks, including many of the most recent releases.

While some artists happily share their work, the major record labels don’t want tracks to leak outside YouTube’s ecosystem. For this reason, they see YouTube-to-MP3-rippers as a major threat.

Several prominent music companies have already taken legal action against key players in recent years. They managed to shut down sites such as YouTube-MP3, blocked others, and are currently involved in a civil lawsuit against FLVTO.biz and 2conv.com in the US.

At the same time, music companies have repeatedly asked YouTube to step up as well. While the streaming site threatened several stream-ripping sites with tough language in the past, it hasn’t taken any strong countermeasures.

However, it appears that this position may have changed. Several operators of YouTube-to-MP3 rippers have confirmed that the streaming service is actively blocking requests from their sites.

“All my servers are blocked with error ‘HTTP Error 429: Too Many Requests’,” the operator of Dlnowsoft.com informs TorrentFreak. As a result, the stream-ripping site currently displays a “service temporarily unavailable, we will come back soon” error message.

The site in question is not alone. Mp3-youtube.download, another stream-ripper, is facing a similar issue. According to its operator, something changed yesterday evening and users now see a ‘this URL does not exist’ error message when they try to convert a YouTube clip.

The massively popular Onlinevideoconverter.com, which is among the top 200 most-visited sites on the Internet, appears to be affected as well. While videos from sites such as Vimeo can still be converted, YouTube links now return the following error message.

None of the site operators we heard from was warned by YouTube in advance.

We also reached out to the video streaming service for a comment and further details, but at the time of writing, we have yet to hear back.

While YouTube’s efforts, intentional or not, are effective, they will likely trigger a cat-and-mouse game. The operator of a popular stream-ripper, who prefers to remain anonymous, managed to get around the blockade by deploying several proxy servers.

Many other stream-rippers and YouTube converters such as FLVTO.biz and 2conv.com are still working fine as well, but it’s not clear whether they were actively targeted by YouTube.