>>40
That's the way copyright law works. By default you have no rights to another person's work whatsoever. Both the BSD license and the GNU GPL grant you additional permissions besides the "you can't do jack shit with this" guaranteed by international treaties etc.
The main difference between the two is that the permissions granted by the GNU GPL are
conditional, as required by its explicit design goal to guarantee and expand software freedom. From this perspective it's quite odd that we have BSD fanboys screaming and ranting that software licensed under the GNU GPL should instead be licensed under a two-clause BSD license. What are their goals? Are they planning to "improve" that source code and then close it off? Or "improve" it and release the changes, which the GNU GPL explicitly permits itself?
Besides permitting proprietary forks and "not being by the FSF who are dirty hippie communists", there is no point to the BSD license at all. Software that one wants to be permitted to be linked against non-free software can be licensed under the Lesser GPL. For reasonable, cooperative people the GNU GPL and its Lesser sibling cover all bases as far as source code is concerned. Only those who would like to make Free Software non-free would want it released under a BSD-like license.
As for people who release their own programs under a BSD-like license, I have no idea where they come from. I'm tempted to say that they are the idealist fringe, which crops up in any popular movement (and Free Software certainly is that), but the absence of patent-based takeover protection in the license makes this improbable. It's as though they were inviting others to claim patents on their own production and have it closed off for the next 20 years for some butthole's proprietary benefit.
In short, use of the BSD license for newly-written software is insane. There are no upsides to it that weren't tied to business models oriented around non-free software, and it is weak against attacks that were well-known more than twenty years ago.