Who do you pay it to? Who do most people pay it to? How do the people who need it typically get it?
Most Muslims also sponsor Orphans. I am actually sponsoring two orphans.
And thus is the First Amendment right to freedom of association destroyed. Fuck you, NSA.
IMagine the huge sum of money which is different pool than tax money.
Large pool of money will attract attention and political pressure from dishonest individual in power.
And, when the agency is only focusing its effort in collecting the alms instead of distributing it to the needy, then the pool will only get bigger, and be the source of tension within society rather than 'peace of mind' force.
so far there is no 'huge' scandal erupt yet. The key terms here is 'yet'.