I am afraid you are wrong here. GPL'd software need not be open to any third party. ie, If I sell you a GPL'd software I should give you the source also along with the binary. But I need not give your friend the source of same same software till he purchases it.
Thanks. I stand corrected. I quote sec 3.
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:
* a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,
* b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,
[....]
The important point to note is that the first para says "...you also do *one* of the following..". Since the party involved is already distributing source to the customers, (which is (a)), he does not need to do (b).
thanks Dileep, for pointing this error out.
best regards ramakrishnan