IANAL, but I don't think so. Practically, probably; legally, unknown. > The above copyright notice and this permission notice shall be included in all copies o

IANAL, but I don't think so. Practically, probably; legally, unknown. > The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. That makes it sound like ripping the license out and replacing it with a proprietary one, even for purely internal use, is probably a bad idea. I don't know who'd be able to sue them for that, though, if the original copyright "owners" aren't supposed to have seen it in the first place. Article II of the GPL has a specific exception for transferring GPL-ed software to employees to work on without letting them spread it beyond that, but I don't know how much of this that would cover.