“Congress must understand the size, scope, and duration of Hamas’s digital asset operations, as well as whether the United States has had success in seizing illicit digital assets,” the letter said. “It is important to understand the scope of Hamas’s digital assets fundraising campaign in the context of its traditional funding activities. Not accounting for the funds Hamas receives from Iran or through donations, it is estimated that Hamas’s global investment portfolio generates hundreds of millions of dollars in revenue. This could far exceed the amount Hamas has received through digital asset donations.”