$BTC came to Bitcoin (BTC), but it cannot be confirmed that they are 'collecting' BTC in the literal sense. Some notable activities include:

1. Seizing BTC: The U.S. government, through agencies such as the Drug Enforcement Administration (DEA) and the FBI, has seized a large amount of BTC from criminal-related arrests, including activities such as money laundering and fraud. For example, in cases like the 'Silk Road' (online black market) or the hack of the Bitfinex exchange, the U.S. government confiscated thousands of BTC.

2. Selling BTC: On some occasions, government agencies have sold BTC that they seized through public auctions. This is not a long-term holding but rather the action of transferring seized assets.