[noosphr]

Of course it can be enforced. If you're not compliant with the terms of a license you don't have a license and are a pirate. If the license is nonsensical then no one can run the software.

[dwheeler]

No, there is no reason to believe it can be enforced.

In the US, training is considered fair use at this time, and thus DOES NOT require a license at all. That might change, but I doubt it.