... lines of the Fourth Amendment been erased?
This is not a scholarly paper, but it does list many issues that have arisen, so don't expect it to be all inclusive, and order of things may be mixed around.
Over the years we have seen many things happen to our protection from illegal search. It is true that many true criminals have been caught, but do the ends justify the means. Does the incorrect criminalization of citizens justify catching a bad guy?
We have dealt with military and law enforcement aircraft flying around looking down on both private and public property, and reporting everything they see.
We have satellites looking down and photographing both public and private property for governmental agencies' use.
Now, recently, we have some new revelations:
1. A recent poll shows that a large majority of citizens approve of governmental snooping into emails and messaging for security and safety purposes without warrants;
2. The Courts are currently ruling that we cannot restrict, deny, or "defend" ourselves from drones over our private property;
3. Security searches have moved from airports and arenas, where we agree to it when we engage in a business transaction, to stop and question and even frisk in public settings for no more reason than a subjective "feeling" by law enforcement.
4. As a commercial driver I also face two issues most people don't: Commercial vehicles can be pulled over at anytime for an inspection of equipment, driver, and cargo details; and in an accident, regardless of the situation, the commercial driver is automatically presumed guilty until proven not guilty (notice I did not say innocent). While a car driver will get a field sobriety test and breathalizer, a commercial driver gets hauled to a hospital to be blood and/or urine tested. In Minnesota we have what are called Whiskey Plates. These are a license plate given to repeat DWI drivers. They can be stopped and administered a sobriety test up to once per day for no reason other than a random spot check. People are screaming this is unfair. Commercial drivers can face this several times a day as the drive across our region and nation.