> the GPL says that i can't allow anyone to obtain a copy of a binary on my hard drive unless i also allow them to obtain the source for that binary. which means that if i don't have the source the GPL requires me to either download it and use up a ridiculous amount of hard drive space to store it, or make sure no one else can read any binaries of GPLed software on my computer.

Please, reread the GPL. At least for v2 it says the following:

> For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code.

> You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following:

> c) Accompany it with the information you received as to the offer to distribute corresponding source code. (This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer, in accord with Subsection b above.)