Islamic law requires a 2.5% tax called zakat which is imposed on income and accumulated wealth of all devout Muslims.
ie. the muslims that are involved in the halal industry- the imams, slaughtermen, workers, business & shop owners etc.
Halal certification is done on a fee for service basis, with the fees varying with the scope and scale of the services.
Certification is provided by Islamic organizations, and would not be halal if the required zakat was not paid on the fees.
What you may not know is that there are eight classes of zakat recipients, each of which gets a 1/8 share of the gross.
One of those classifications is fighters in Allah’s cause aka Mudihideen, aka terrorists.
When you purchase a product which is certified Halal, you are indirectly contributing to terrorism.
I quote from Reliance of the Traveller, the Shari’ah handbook of the majority Sunni sect of Islam.
h8.7: The Eight Categories of Recipients
It is obligatory to distribute one’s zakat among eight categories of recipients (O: meaning that zakat goes to none besides them), one-eighth of the zakat to each category. (n: In the Hanafi school, it is valid for the giver to distribute his zakat to all of the categories, some of them, or to confine himself to just one of them (al-Lubab fi sharh al-Kitab(y88), 1.155). )
h8.17: Those Fighting for Allah
The seventh category is those fighting for Allah, meaning people engaged in Islamic military operations for whom no salary has been allotted in the army roster, but who are volunteers for jihad without remuneration.
They are given enough to suffice them for the operation, even if affluent; of weapons, mounts, clothing, and expenses for the duration of the journey, round trip, and the time they spend there, even if prolonged.
Though nothing has been mentioned here of the expense involved in supporting such people’s families during this period, it seems clear that they should also be given it.