Originally Posted by
trentmidds
Everyone that enters the USA is required to clear customs at the point of entry (SFO in your case) even if they are flying somewhere else.
With the exception of Air NZ passengers, travelling LHR-LAX-AKL or AKL-LAX-LHR.
http://www.airnewzealand.co.uk/befor...ing-via-la.htm