"Jihadi" groups and Bid'ah
There have been posts by another user-not-to-be-mentioned-by-name who has attacked fellow muslim groups for mostly not being too worried at jihad and doing a bad job of it.
But the probably is that by all accounts, most jihadi groups engage in bid'ah (while accusing others of it).
Or if you go by Imam shafi'i's view, then bid'ah sayyi'ah.
Bid'ah is according to Shaykh Ibn Taymiyyah something which contradicts Qur'an and Sunnah. (According to Imam Shafi'i's opinion bid'ah sayy'iah is something which contradicts Qur'an and Sunnah. I will refer to both as simply bid'ah in this post).
Now what is this bid'ah that the jihadi groups do? indiscriminate murder for one.