We are talking about guys who drive armored cars loaded with chemical weapons in suicide attacks en mass towards their enemies.
To call them superstitious morons isnt an insult,its a fact.
"And why not eat of that (meat) on which Allah's Name has been pronounced ( at the time of slaughtering the animal), while he has explained to you in detail what is forbidden you, except under compulsion or necessity?" al-An'am 6:119
While there is more material on this in both the Quran and the Sunnah this is the shortest single quote and it will suffice. According to this Surah there are cases in which the consumption and therefore contact with a swine is allowed (same for alcohol) according to numerous fatwas this pertains to:
1. Consumption of a najaasah (impure) object (maitah, pork or alcohol) is permissible if the person fears death by hunger or thirst. Thus you can consume something that is haraam if you have to in order to survive.
2. Speaking word of Kufr during torture or when subjugated. As in captured and forced to do so by your captors. Or even through Taqqiyyah.
3. Warding off an aggressor whether in war or in peace. As in a pig battalion sent at a Muslim army.
Therefore Daesh, would pull up these rulings to allow themselves to do so, same for any Muslim army.
If you doubt this, check fatwa number 130815.
The main rule Daesh or a Muslim army would need to fulfill which would be time consuming is the cleaning up of the swine flesh after the battle or of fallen allied soldiers, which would probably need a fatwa and discussion to decide the correct cleaning methods of a fallen Muslim who is covered in swine flesh.
The cleaning of najaasah is covered in fatwa number 20843
) problems even without shooting enemies. So that's why probably even crusaders haven't used pigs. But there might be other reasons too.
