because Mr Google has so decreed that all sites that are not latest security ht_pps driven are so - basically driven by public wifi usage in which such 'insecure' sites may have pages altered or some malicious javascript added to the page by the owner of the wifi transmitter - no problem if you are using a landline or your own domestic wifi link. Why should Google worry - well certain people operating such wifi's in cafes etc had realised that their free wifi could be made to pay for itself by stripping out Google inserted adverts and replacing them with their own.