Incidentally, the Royal Society has its own archive; this is not from JSTOR.
The Royal Society's archive looks just as walled up as JSTOR's. I picked out an arbitrary volume from 1693 and tried to get the full-text PDF for a paper, but it asks for a login. I don't know if anyone can signup for free or has to buy an access package — in any case, it seems unnecessary to make people jump through hoops for papers that are (in their original form) public domain.
http://thepiratebay.org/torrent/6554331/Papers_from_Philosophical_Transactions_of_the_Royal_Society__fro
Greg Maxwell is torrenting 33Gib of public domain JSTOR documents that were behind paywalls.
What's your take on this, ethically, legally, etc?
ETA: More on this: http://gigaom.com/2011/07/21/pirate-bay-jstor/