Hmm. Either they never expected anyone to get their hands on it, using the encryption in a less serious way (In other words, to deter the casual), or they were stupid, or they intended the computers to be found...

Some have suggested that the reason that DES was made an open standard, and then the NSA and FBI began whining about export control, was so that people would adopt DES, thinking that the NSA couldn't crack it. (Because they didn't want it exported.) In reality, as the theory goes, DES was ALREADY crackable or had a hidden weakness, and it was all a trick to get possible enemies of the state to use DES...