Although I don't have access to the proprietary code used, it's most likely that an LSH algorithm is behind the scenes in every modern search engine (to avoid serving duplicates), many modern ranking systems such as Elasticsearch (because items are typically vectorized and retrieved based on these vectors), and most recommendation systems (for similar reasons as ranking). For example, all of these pages probably have an LSH algorithm at some point (either batch processing before your request, or in some cases real-time lookups):
* Every search result page on Google * Every product page on Amazon (similar products) * All music suggestions on Spotify or similar * Every video recommendation from TikTok, YouTube, or Instagram
etc.
You can first run the contents through some sort of embedding model (e.g. the recent OpenAI embedding model [1]), and then apply LSH on those embeddings. The documents that have the same LSH value would have had very similar embeddings, and thus very similar content.
You can almost only check objects that inhabit the same buckets (there are caveats, usually neighboring buckets are also checked), eliminating objects that couldn't possibly collide by virtue of e.g. being on the other side of the map. Of course this is still O(n^2) because every object could be in the same bucket (but that's unlikely).