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Orin Kerr:
The first change is a clarification that FISA warrants are not needed for "surveillance directed at a person reasonably believed to be located outside of the United States." That is, if the government is monitoring someone outside the United States from a telecom switch in the U.S., it can listen in on the person's calls and read their e-mails without obtaining a FISA warrant first. The Fourth Amendment may still require reasonableness in this setting when one or more people on the call of e-mail are inside the U.S. or are United States citizens, but there is no statutory warrant requirement.
http://www.volokh.com/posts/1186332672.shtml
(JaO comments on the Fourth Amendment question in the Lederman post you pointed to.)