Like many other academic journals, Molecular and Cellular Biology takes copyrights very seriously. And to trace the criminals who share scientific publications funded by public institutions, they add to the margin of the pdf reprints downloaded from their website the date and the identity of the license owner.
I recently heard that some people downloaded and installed the pdf toolkit pdftk and at the Linux terminal issued a command like the one below, where they replaced
article.pdf by the name of the pdf they had downloaded.
pdftk article.pdf output uncompressed-article.pdf uncompress
Using their text editor, they opened the uncompressed pdf file and looked for lines like the ones below and commented them out with a % sign (or even deleted them, just in case).
10 0 0 10 0 0 cm BT
/R19 11 Tf
0 -1 1 0 579.5 456.847 Tm
[( on some day by Institution of the Evil Person)556]TJ
-94.148 0 Td
-89.2543 0 Td
[(Downloaded from )278]TJ
They then ran pdftk again to fix the pdf document, and the download information was gone.
pdftk uncompressed-article.pdf output...