1) Most people "all over world" are not US citizens and therefor not covered by bill of rights "that our founding fathers fought for" (according to US Government). NSA does (claim) to attempt to identify communications of US citizens it intercepts "overseas" and doesn't look at them without cause.
2) NSA breaks the law. Routinely it would appear.
http://scholarship.law.georgetown.edu/cgi/viewcontent.cgi?ar...
Just because its a reason they give, doesn't make it valid - but I guess thats what your #2 was addressing =)
Note I'm not making a normative statement here; rather I'm agreeing with the previous statement that this is FedGov's claim about the extent to which the BoR applies to non-US citizens abroad.
E.g. while it hasn't reached the Supremes, a bunch of states that have shall issue concealed carry regimes have been forced by the courts to extend these to permanent resident aliens (AKA Green Card holders), who in general are pretty much treated as citizens except they can't vote and of course can be deported.
btw "(according to US Government)" should have made it clear that it was a reported fact and not a value judgement by the author, me.