1) Venmo took the money, not the government.
2) Again, so :
how many times has someone used Venmo to transfer money to ISIS and included the word "ISIS" in the memo
You're saying that we should just assume that, because it's patently ridiculous for the average American to actually mean "ISIS" when they type it into a memo identifying a transaction (and why is it patently ridiculous other than because it seems absurd/uncommon?), we should assume "ISIS" is never deliberately used to actually, you know, identify ISIS?
That is like saying that every time someone labels a transaction "Door Purchase," we should assume it's not actually for a door purchase, because no one ever purchases doors, of course!