License can prohibit reproduction of public domain data

ILLINOIS–Terms of a software license could prohibit a customer from reproducing a database of telephone listings that are in the public domain, the U.S. Court of Appeals in Chicago (7th Cir.) ruled in late June. Telephone directory information has traditionally not been protected by copyright law.

In 1994, Matthew Zeidenberg purchased a copy of SelectPhone, a CD-ROM database released by ProCD, Inc., containing information from more than 3000 telephone directories. Zeidenberg then formed Silken Mountain Web Services, Inc., and made the information — but not ProCD’s proprietary software — available via the Internet.

The court held that while federal copyright law pre-empts conflicting state laws, copyright interests can be limited by parties to a private contract, even if the material is in the public domain. If Zeidenberg objected to the terms of the license, he was free to return his copy of SelectPhone, the court ruled.

The court noted that the same principle is well established for other types of information that cannot be protected by copyright. Copyright law would not invalidate a contract not to reveal trade secrets, nor would it override the agreement of a video store customer only to use rented tapes for home viewing.

Occasionally, this principle might sufficiently interfere with “national objectives” to require that it be pre-empted by the Copyright Act, the court added. But in this case, the information in SelectPhone remained in the public domain. Zeidenberg could only recompile the data from the original phone books, the court ruled; he was not entitled to undercut the labor of ProCD by violating its software license. (ProCD, Inc. v. Zeidenberg)