Might be a UK thing, it’s the standard size in multi packs. Asda

My guess is pirated material.

Distribution of User Content may be subject to third-party rights. You agree that by using the Plex Solution you will not upload, post, display, or transmit any of the following:

anything which defames, harasses, threatens, offends, or in any way violates or infringes on the rights (including, without limitation, patents, copyrights, or trademark rights) of others;

I’m assuming that benefit of hosting Plex somewhere is that it scales to multiple users better when running/selling Plex as a paid service and this is too visible for their plausible deniability.