[eridius]

Distribution in any fashion of any GPLv3 code counts as implicit acceptance of the license, which kicks in all the nasty stuff in there, including the virality of it (so the rest of your code now must be GPLv3), the anti-tivoing clause, the patent crap, etc.

[gizmo686]

Licenses are not contracts. Although it is not nessasary for the GPL to make that point explicitly clear, it does:

You may not propagate or modify a covered work except as expressly provided under this License. Any attempt otherwise to propagate or modify it is void, and will automatically terminate your rights under this License (including any patent licenses granted under the third paragraph of section 11).

In other words, if they violate the anti-tivoing clause, then they loose the rights granted to them by the GPL, so they no longer have the right to use the software in their produce. In other words, the worst a license agreement can do is make you break copyright law.