This nation's computer software industry needs protection from pirates who pick their pockets with copies and cheap rentals.

The loss comes to an estimated $4.1 billion a year and is bound to get bigger unless Congress acts. If the practice continues, it can be expected to sap the incentive of software producers to keep developing new and better products.That much should be clear from the hearings that Sen. Orrin Hatch has been holding in Utah this week on his bill to prohibit unauthorized rental or leasing of copyrighted software programs.

It won't necessarily be easy to resist present trends. Entire industries have sprung up around the American penchant for making copies of things. Among such industries are video recorders, copy machines, and cassette tapes. Behind those industries is a general inclination to let people make copies as long as they are only for their own, non-commercial use.

But when there is one pirated copy for every legitimate copy of a computer software program, it should be clear that some people are abusing their freedom.

The software makers are not trying to prohibit the rental of software. Nor are they trying to impose a sweeping tax or force the installation of built-in shut-off devices as the music industry has suggested in an unsuccessful effort to thwart the recording of music from radio and records.

Instead, all the software industry asks is that the holders of copyrights on software programs be given the right to authorize their rental.

Unlike other well-developed industries involved in making other kinds of copies, the software copying and rental industry is still just in its embryonic stage. Congress should act now before the abuses get far worse than they already are.