The case is called Edward Haase v. William Webster, et al., and the defendants are charged with having violated the free association and free speech rights of an American, Haase, who recently returned from a trip to Nicaragua. Also at issue is this traveler's right to privacy.

The plaintiff's lawyer has resoundingly invoked, in the court papers, Lord Camden's famed 1765 rebuke of the British government for having seized books and private papers in the home of a clerk who worked for a newspaper critical of the government. Said Lord Camden:

"We can safely say there is no law in this country to justify the defendants in what they have done; if there were, it would destroy all comforts of society; for papers are often the dearest property a man can have."

The present case began on Jan. 16 of this year when Edward Haase, a broadcast engineer and free-lance journalist in Kansas City, Mo., arrived at Miami International Airport from Managua. Haase is a member of the National Network in Solidarity with the People of Nicaragua. It can safely be assumed that he is not a fan of the president's policies in Central America, but the same can be said of certain bishops and members of Congress.

As Haase was going through customs, an official of that service separated his books, newspapers and magazines from the clothing and other articles in his baggage. A while later, an FBI agent, Joe Miranda, introduced himself to Haase and escorted him into a separate, closed room where the special agent asked Haase why he was interested in Nicaragua and whom he worked for there.

According to Haase's affidavit in the case, Agent Miranda concluded the first stage of his business with the traveler by saying that the FBI has certain rights and that one of them is the right to search for subversive literature. Miranda added that he was about to do just that.

The special agent proceeded to put to one side Hasse's address book, which, Haase says, "contains names, addresses and phone numbers of social friends, political activists and other associates, political organizations and journalistic contacts." Miranda also took special interest in an 80-page diary, a spiral notebook, in which Haase had written his reflections on his trip.

In addition, the man from the FBI was much taken with five pages of names, addresses and phone numbers of organizations -- and contact persons in them -- concerned with Latin America. Miranda wanted to know if these were pacifist groups. Does the FBI now have a pacifist desk?

Miranda, also glommed two typescripts of articles by Haase, one about the celebration in Nicaragua of the "Immaculate Conception," a religious holiday. (Symbols can be particularly dangerous.)

Later that long afternoon, the traveler saw FBI Agent Miranda and an assistant at a copying machine where they were duplicating Haase's address book, diary and other papers. Some time afterward, Miranda returned the originals of all the materials he had taken. They were not contraband, therefore. So what was the FBI agent doing with them in the first place? Anyway, the traveler was free to go, but he had left part of himself behind in the possession of Special Agent Miranda.

After his rather disconcerting experience, John Haase told all his associates that their names, addresses, phone numbers and organizational affiliations were now in the possession of the FBI. It is not the sort of news that makes anyone's day, even if he is wholly innocent of wrongdoing. Especially if he is innocent of wrongdoing.

Haase also retained a lawyer, Michael Ratner, of the Center for Constitutional Rights. Ratner, who has had considerable experience in dealing with law enforcement agencies that count the Bill of Rights among their permanent enemies, has secured a temporary restraining order from U.S. District Judge Thomas Jackson in Washington. Under this order, the FBI cannot disseminate the fruits of its search and seizure of Haase's papers, and it must get back -- and place in the personal custody of William Webster -- whatever it has circulated to other FBI offices and to intelligence agencies.

There will be another hearing on

March 19. Ratner will press for guidelines to restrain government agents from

again subjecting travelers to the kind of

political search and seizure that Haase

has experienced.

After all, as Supreme Court Justice Robert Jackson noted in a 1949 case: ". . . among deprivations of rights, none is so effective in cowing a population, crushing the spirit of the individual and putting terror in every heart. Uncontrolled search and seizure is one of the first and most effective weapons in the arsenal of every arbitrary government."

Meanwhile, Michael Ratner is advising Americans who plan to travel to Nicaragua to leave their address books at home and not to keep a diary while they are there. Carrying a photograph of Ronald Reagan, however, should cause no problems.