During the past six months the Federal Bureau of Investigation has come under fire for its use of electronic devices--telephone wiretaps and hidden "bugs"--to gather evidence to fight crime and protect the national security. Last summer the Supreme Court nullified a tax evasion conviction on the grounds that evidence used was obtained illegally. Throughout the summer and early fall, there were strident cries for statutory limitations on such activities--with particular reference to those carried out by the F.B.I. And last weekend, F.B.I. director J. Edgar Hoover and his former boss, ex-Attorney General Robert F. Kennedy, accused each other of being responsible for the buggings from 1961 to 1964.

In fact, early in the Kennedy Administration, the Attorney General ordered the F.B.I. to clear all its wiretapping activities with him. More recently, the courts have frowned on all electronic snooping except in the interests of "national security."

The rationale for these restrictions is that the continued use of the electronic devices tends to have a chilling effect on the right of all citizens, even suspects, to free speech. The conflict, of course, arises over "national security," which often takes precedence over the protection of civil liberties. But the F.B.I.--as a subordinate part of the Justice Department--should not have discretionary authority in this area. The courts or Congress, if possible, should establish precise guidelines.

In the last week, however, it has been made all too clear that past restrictions on bugging were regularly ignored by the F.B.I. William G. Hundley, the former chief of the Department's organized crime section, stated last Tuesday that he was aware of the extent of F.B.I.'s activities, but that Kennedy apparently was not. In addition, he charged that the F.B.I. blatantly lied to him whenever he asked about bugging.

Mr. Hoover, as everybody knows, has never been too forceful an advocate of civil liberties. He has always worried more about apprehending and jailing the culprits. And the Attorneys General under whom he has served should have assumed this and limited his free wheeling activities, even if they have become a minor tradition in America.

Later this month, the National Crime Commission is expected to recommend legislation to the President to expedite law enforcement. It should definitely propose a bill to curtail federal agents' bugging activities. Exceptions--which will be necessary in some instances--should be granted individually by the courts. Congress should codify the principle that effective prosecutors should not infringe on the civil liberties of alleged criminals.