Is cash becoming illegal?
Regardless of what you think about the seriousness of the threat posed by the BTCA to the idea of physical currency, make no mistake: powerful, well-funded forces are determined to push for a world that functions entirely on digital currency.Collect a few hundred dollars, go directly to jail...
Already in the United States, possession of any substantial amount of cash is considered de facto evidence of criminal wrongdoing. Consider that federal law requires banks to immediately report any customer who withdraws more than $10,000 in cash from their own banking account to the federal government, so that law enforcement agents can promptly question the offending customer about their intentions and the disposition of the withdrawn cash. Note that moving an equivalent amount of digital currency from place to place carries with it no such reporting requirement, presumably because it is already easier for the government to track digital currency.
Additionally, law enforcement agencies have increasingly begun to treat the mere possession of large sums of cash as sufficient evidence of criminal wrongdoing to justify seizure of that cash under civil asset forfeiture laws.