WASHINGTON (AP) _ Lots of folks who have found themselves in confrontations with a landlord or the police or a particularly obnoxious neighbor have at some point sputtered, ``I know my rights.''

But do we?

Why can Hamilton College in Clinton, N.Y., ban students from forming single-sex fraternities and sororities but the State University of New York at Buffalo cannot? Don't students everywhere have a right to associate with whom they please?

How could Shannon Faulkner get a federal judge to order The Citadel to admit her as a cadet but could have no chance of success getting into most other males-only colleges?

And how can a perfect stranger walk up and punch you in the nose without violating your constitutional rights?

``Americans don't understand that many `rights' are really liberties _ freedom from governmental interference,'' says Richard Seeburger, a University of Pittsburgh law professor. ``They only work against the government.''

So unless that rude stranger whose fist met your nose is a police officer, a disgruntled postal employee or someone else on official government business _ people ``acting under color of state law'' _ no constitutional violation occurred.

Such attackers, however, surely can be arrested and prosecuted _ and even sued for civil damages.

Local, state and federal lawmakers are not shy about bestowing additional rights.

The ``right'' to safety is protected by making an unprovoked punch a violation of at least one law, and probably lots more.

And American ``common law'' is a source of legal rights even older than the Constitution.

Hamilton College cannot violate students' constitutionally protected associational rights because it's a private school, not run by the state as are SUNY Buffalo and The Citadel.

Ms. Faulkner's demand for equal protection under the 14th Amendment could succeed only against public schools because they are agencies of the government.

They and their employees can be found to violate someone's constitutional rights, while private schools _ and private citizens _ generally cannot.

But private schools that accept federal money likely will find all kinds of statutory strings attached, such as anti-discriminatory laws that mirror the Constitution's insistence on equal treatment.

Rep. Robert Livingston, the Louisiana Republican who chairs the House Appropriations Committee, recently wrote to the presidents of Hamilton and three other private colleges to complain about their bans on single-sex fraternities and sororities.

Livingston, a former prosecutor, knows that only a state-run school can be found to violate a student's constitutional rights. ``Your colleagues at the public schools are absolutely banned from the type of discrimination that you are practicing,'' he said.

``As the beneficiary of significant federal funding, one would think you would be sensitive to the bedrock principles of freedom of association and the liberal arts tradition,'' Livingston said.

Asked if Livingston planned to press legislation to force the issue, spokesman Quin Hillyer said: ``I don't know if this will go any further.''

The Constitution's first 10 amendments, collectively called the Bill of Rights, were intended as checks on the power of Congress. The 14th Amendment's promise of due process and equal protection later was interpreted to extend many of those limits to state and local governments as well.

``The state-action doctrine is easy for most purposes,'' says University of Minnesota law professor Susannah Sherry. ``But it can get complicated in some circumstances.''

For example, the Supreme Court ruled in a 1948 case that the Constitution does not prohibit private citizens from agreeing to keep blacks and other minorities out of their neighborhoods by refusing to sell or rent to them. But it said the 14th Amendment prohibits state courts from enforcing those restrictive covenants.

Such enforcement would amount to ``state action'' denying equal protection, the justices concluded.

For the record, there's only one circumstance in which a private citizen not acting as a government agent can violate someone's constitutional right _ by enslavement.

The 13th Amendment banning involuntary servitude has no state-action requirement written into it.

___

EDITOR'S NOTE _ Richard Carelli covers the Supreme Court and legal affairs for The Associated Press.