I think the plausible deniability comes from the fact that just because a certain pattern of bits happen to occur in some movie does not mean they ONLY happen in that movie. In fact, that certain pattern of bits by itself is nothing more than reasonable use or a short "quote" at worst and at best simple free speech. If the RIAA and MPAA claim "ownership" of "all patterns of bits from any subset of any format that encodes their copy righted works" then it could be argued that we are all guilty already by pure random chance!
You might like offsystem.sourceforge.net and blocksnet.sourceforge.net
OFF is a highly connected peer-to-peer distributed file system. The unique feature of this system is that it stores all of its internal data as meaningless multi-use data blocks. In other words there is not a one to one mapping between a stored block and its use in a accessed file. Each stored block is simultaneously used to access many different files. Individually however, each block is nothing but arbitrary digital white noise.
No creative works, copyrighted or not, are ever communicated between OFF peers. Only meaningless blocks of arbitrary data. No tangible copies of creative works are ever stored on OFF peers. It is completely unnecessary.
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Instead of working on whole files however, OFF works exclusively with fixed length blocks of data. Each block is exactly 128KB in size. If a file being stored is longer, it is broken into multiple 128KB blocks. If it is shorter, the blocks are padded to 128KB with random data.
These initial source blocks are never stored in the OFF System. Instead, OFF arbitrarily chooses relationships among new or existing blocks that happen to XOR back to the source block.
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