[Dan Evans]

The fourth Amendment does not require a warrant, it only requires that a search be "reasonable", whatever the he!! that is.

It means a police officer can't do a search unless he has a good reason to believe that the person being searched has committed a crime.

[porkchops 4 mahound]

Yes, that is what it is supposed to mean.

(Subject to the interpretation of the courts, which is why there is "some" doubt.)