Not actually - suppose an airline said - No blacks, or no person over 300 pounds.... ect
Remember you said "any thing"
That's right. It is a private business and the plane is private property. They can make any rule they want. Of course if they make a rule regarding one of the protected people under USC 42 Section 1983 they are also free to defend themselves in a court of law.
Governments job is to (reasonably) protect me from others
No, it is not. The US Supreme Court ruled that not only is it not the government's job to protect you, but that even the police are under no obligation to protect any individual.
- and that includes not just those flying on the plane, but anyone who could be harmed - ie a plane flying into a building - (like that would ever happen)
How does robbing me of my civil rights make you any safer?
and why is it people only complain about the pre boarding searches.
Do you realize
how many regulations the FAA has?
Completely different issue. The states can set speed limits on all highways including federally funded highways, but no police officer has the right to stop me and search my car without probably cause or the issuance of a warrant.
can you imagine the confusion there would be if each airline had its own security?
You mean before 2003 when all airport screeners worked for the airlines and not the government?
Do you honestly think it is easier and with less confusion now than it was in 2000?
I used to fly over 100,000 miles per year. All TSA has done is violate people's rights and take cuticle scissors and knitting needles away 80 year old women.
How many air disasters or hijackings has TSA prevented? (I will give you a hint, it is a number between +1 and -1 - yeah, that's right, NONE!)
By the way, airports have the option to opt out of government TSA security and do it themselves. The following airports are just a few that have opted out of the TSA mess: Charles M. Schulz-Sonoma County Airport (STS); Dawson Community Airport (GDV); Frank Wiley Field (MLS); Greater Rochester International (ROC); Havre City County Airport (HVR); Jackson Hole (JAC); Joe Foss Field (FSD); Kansas City International (MCI); Key West International Airport (EYW); L.M. Clayton Airport (OLF); Lewistown Municipal Airport (LWT); Roswell International Air Center (ROW); San Francisco International (SFO); Sidney Richland Regional (SDY); Tupelo Regional (TUP); Wokal Field (GGW). One of the latest, and busiest is Sanford/Orlando. And, guess what. Their safety/security record is better than the TSA airports!