I updated the description with some reasons. :)

Thanks! I'm being told this model is being used in a media computer science AI course at HTW uni in Berlin, Germany. There's a licenses.txt file in the exercise which contains attribution.

I removed a few sounds on my freesound military sfx pack after a comment - probably by leilei (undesired) - claimed they were protected. (this was probably in 2012) I had to agree that they sounded a bit too good to be self made by us military and remembered that the video from which they were taken seemed very edited sound-wise, when I ripped them from us military video material back in 2009, naively thinking "they probably made sure they have the rights to publish the result as public domain material".

It would be really helpful if the filename was pointed out (I assumed you mean the ExplosionMetal*wav files) and if there was a way to prove that the sound actually was originally from a sound library (not easy if the libraries aren't online available legally in the case of soundideas of course). If you could have been able to point out the exact soundideas sound pack, it would have been helpful.

So I couldn't confirm that the sound was taken from a protected library but figured better safe than sorry and that leilei is more experienced at tracking down protected game assets, so now this submission contains a different explosion, which is taken from a military video recording, which did not make the impression of being edited - http://www.freesound.org/people/qubodup/sounds/67474/

Cheers

swlu, thanks for releasing and sharing the tracks under cc-by3!

andrelopes1993 freesound.org has the sounds you're asking for. Remember to give attribution to the authors! :)