I have noticed a disturbing tendency for folks to make documents "available" for downloading or printing but only if one "signs-up" for x, y or z service.
There is a reason I have a throw-away email, ( and do not and will not use gmail), and also a reason why I will not sign-up to one of those download sites. It is part of OPSEC.
I am fully aware that IP addresses can be logged and co-related back to a particular computer, (unless I go to wayyyy more trouble than I think is necessary at this time), but why should I make that process any easier by just logging in to a service that is going to ask me a bunch of impertinent questions to allow me to download a document someone is making available for "free". Sure... I have their "assurances" that I am not being logged and that my info will not be given away but do I really want to place my faith in that, (think AOL and it's previous disgorgement of private emails to "law enforcement" without so much as a warrant).
BTW I do appreciate the fact that, in most cases, you tend t.o copy an entire article instead of making us link out to it.