The key to stopping terrorism is to stifle their access to money. That means targeting the financiers on the one end of the system who pay money in to banks, and the operatives at the other end of the banking system taking the money out to buy materiel for their acts.
Law enforcement and companies, and banks, need information about the identities of the pay masters, they need to know who is likely to withdraw the money, but most importantly, they need to be able to follow its trail through the world's financial centres. In that respect terrorist financing is a subset of money laundering. This is explained by Nick Kochan in many articles on both law enforcement treatment of terrorist financing, and the terrorist financiers themselves.