I've seen similar concerns raised elsewhere. I think the bill they intend to reference is the requirement to report foreign bank accounts with increased penalty for failure to comply. The argument is that this somehow makes dollars less attractive to foreign investment and as a result crushes the value of the dollar and by extension crushes the US economy. It's a very fear-mongering argument.
I don't know why people are so susceptible to being swept up in these crazes. Whoever is circulating these emails must be very good at getting emotional responses that keep people from understanding and analyzing the actual arguments being made. Perhaps this is similar to why people follow investment guru advice, or political pundits. If the scare is big enough (end of the world as we know it) then even the very remote possibility that that could actually happen seems to get people all excited. I think there are a lot more ways that the US economy could be crushed than a wave of unexpected consequences from enforcing taxation on Americans who are hiding income in foreign accounts, but who knows. The email messages are vague enough and so short on actual details that maybe they mean an entirely different problem. There are plenty of scary problems.