There seems to be quite the concerted effort to obscure what the “compromise” FISA legislation does.  There is a lot of reassuring language about oversight and safeguards, which ignores the heart of the issue.  This is it:

The new FISA bill that Obama supports vests new categories of warrantless eavesdropping powers in the President (.pdf), and allows the Government, for the first time, to tap physically into U.S. telecommunications networks inside our country with no individual warrant requirement. To claim that this new bill creates “an independent monitor [to] watch the watchers to prevent abuses and to protect the civil liberties of the American people” is truly misleading, since the new FISA bill actually does the opposite — it frees the Government from exactly that monitoring in all sorts of broad categories.

What does this mean in practice?  From Balkinization, here is part of the answer:

This sort of “vacuum” surveillance could not be approved under the old FISA scheme, which requires either that the calls be wholly international, or that the interception be made overseas, or that the NSA demonstrate evidence in advance that the target is an agent of a foreign power. Under the new law, the NSA can engage in surveillance where none of those three criteria are met.

There is no obvious limit to the communications that could be targeted for surveillance.  Warrantless wiretapping is unconstitutional and dangerous to a free society.  At the very least, we should understand that the “compromise” bill will give a Congressional rubber-stamp to unconstitutional acts by the federal government on an ongoing basis.