Well, they're not going to have much records of many bitcoin users' trail.
That could be a problem. It could also be something to make the use of Bitcoins in America illegal. Certainly the U.S. government is very interested in "paper trails" and keeping track of where money came from and where it is going, where even cash transactions have to be reported on some level. This move simply adds that issue all that more.
It also goes to show what happens when Congress passes legislation that nobody bothers to read before they vote on it. Depending on dividing it up to all of the "staff" to pour through and see if there is something you don't like should mean that the legislation was bad in the first place.
Yes, I do believe that each congressman should read the whole legislation they vote upon, at least for those they vote "yes" upon. Voting "no" regarding a stack that is incomprehensible does more good for everybody involved.