When my state introduced seatbelt laws they assured the public that they would only be a secondary offense, never the primary basis for getting pulled over and issued a ticket.

Now they run "Officers are watching! Click it or ticket!" as an advertising campaign.

And I'm not arguing that seatbelt laws are bad per se, just that any time there is a pathway for more control, it will eventually be taken, even if assurances are made that it will not happen.