Let's just be analytical for a second about this :
a. For one thing... nobody knows who invented Bitcoin ....yea we all know it's Satoshi Nakamoto, but that could just be a code name for a NSA secret project. I think the terrorist
groups would have considered that to, before they dumped millions of dollars into it.
b. Everyone knows Bitcoin is Pseudonymous... You would be crazy to risk a major operation on something that are not fully anonymous.
c. Weapon merchants in my area, do not accept bitcoins as a payment option.
d. Pushing large amounts of money through Bitcoin exchanges would raise a red flag.
Why would someone want to use a currency with all these weak spots and uncertainties? Cash and fake credit cards and fake ID's are so much easier.
You want to stop terrorist funding? .... Follow the bread crumbs back to the businesses being run in the country where these things are happening. They are doing this in plain
sight, and paying in cash.