Because these are FISA requests for individuals "reasonably suspected to be residing outside the U.S.". Those have never required warrants. Before FISA existed they just did it to whomever they pleased; now it requires a FISA request which is not the same thing as a warrant. Nowhere in that document does it say anything about not needing a warrant to get information on U.S. citizens residing in the U.S. What it does…
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,…
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".