[swiley]

I don’t know if it’s possible for that to happen since the licenses are mutually exclusive.

There are plenty of situations where BSD (or similar) lisenced software is used and the changes are not published.

[jimktrains2]

Just to clarify, you don't need to provide changes to GPL software if you're not distributing said software and only using it internally.

However, in case something ends up being distributed and because I don't believe that's been tested in the courts, many companies have blanket policies against the inclusion of copyleft licenses.