Using unofficial streaming or download sites carries significant risks. Security experts often warn that these platforms can be hubs for malware or intrusive ads.

The term "mkv" refers to the container, an open-source format that can store unlimited video, audio, and subtitle tracks in one file. It is the preferred format for high-definition (HD) movie rips because it supports advanced codecs like H.264 and H.265 (HEVC), maintaining high quality at smaller file sizes. Sites like 123Movies and its various mirrors (e.g., 0123movies) have historically used this format to distribute copyrighted content. Risks of Using Unofficial Streaming Sites

The site's popularity was fueled by its vast library of content, which included Hollywood blockbusters, indie films, and TV shows. Users could download movies and shows in various formats, including MKV, AVI, and MP4, making it easy to play them on various devices.

: These websites host pirated content, which is illegal in many jurisdictions. Governments frequently ban these domains, leading the developers to constantly switch to new URLs.