A few points. A FISA order really is a warrant, and the NSA needs one to collect on a US person (ie. US citizen anywhere or anyone on US soil). Before 9/11, FISA warrants were also used to compel US companies to comply with collection against non US persons for which they were the carrier. At some point after 9/11 the Bush administration realized the law could be reasonably interpreted as not strictly requiring this, so they stopped using FISA for this purpose. That was the heart of the warrantless wiretapping controversy, and the primary goal of the FISA Amendments Act was to add requirements and oversight for these situations.
Not according to the language used in this document it isn't. You can say it is similar if you want, but when they say "A warrant is not required" in this case they are not saying "no authorization is required".
