U.S. senators have proposed the RESTRICT Act, which could prevent Americans from accessing open-source tools or protocols like Bitcoin in extreme cases

ChainCatcher message, the RESTRICT Act proposed by Senators Warner and Thune aims to prevent or disrupt transactions and financial assets involving foreign adversaries that pose a risk to national security. Although the primary target of this legislation is companies like TikTok, the wording of the bill could be used to prevent or disrupt cryptocurrency transactions, and in extreme cases, could also block Americans' access to open-source tools or protocols like Bitcoin.

The RESTRICT Act is conceptually similar to the International Emergency Economic Powers Act (IEEPA), which authorizes OFAC to block transactions between U.S. persons and sanctioned foreign entities. (source link)