Is it true that Citadel and other investment houses are actively shorting Treasuries?

I had heard that some months ago, and the whole idea is insane.

No one anywhere should be allowed to short sell the backbone of the Federal Reserve. There should be no incentive to have the economy fold. Now look what comes from these greedy monsters.

Imagine being granted unlimited power to control the economy as private individuals by the tacit approval of elected officials, and then after you’ve ransacked and pillaged the stock market in every way possible, when your bad bets work against you and you get trapped, you short the hell out of T Bills, Bonds, and Notes and then use your power to crash the economy utterly, and make a bundle for doing so.

Can someone please put a halt to this immediately, by any means necessary?? (or is that only for them)