More fun publisher surveillance:
Elsevier embeds a hash in the PDF metadata that is *unique for each time a PDF is downloaded*, this is a diff between metadata from two of the same paper. Combined with access timestamps, they can uniquely identify the source of any shared PDFs.

@aral
pay $5 for 2 albums a month, stream the rest for free, .85*10=$8.5 to artists
pay $10 to Spotify and stream the average 25h of the average 3:30 song ~= 500 songs * $.00318 per stream = $1.60 to artists.

@aral
gotta give it up for our tru love ~bandcamp~ whose default free to stream, money to the artist model gives thousands of times more revenue to artists than subscription streaming platforms