Because how trivial would it be to modify a PDF maliciously and change data, forge results, etc.?
The same reason why we encrypt traffic using TLS, even if it's "mundane" traffic like tweets.
The same reason why we encrypt traffic using TLS, even if it's "mundane" traffic like tweets.
Targeted attacks might be possible based on the file contents or using a side-channel to ID the downloader; meaning only specific targeted users would get the malicious files.
Either way, being able to hold Sci-Hub accountable as this source would be important.