Says the article:

... the other two members—Rachel L. Brand and Elisebeth Collins Cook, both of whom were Justice Department lawyers in the George W. Bush administration—rejected the finding that the program was illegal. They wrote in separate dissents that the board should have focused exclusively on policy and left legal analysis to the courts. Last month, two Federal District Court judges reached opposite legal conclusions in separate lawsuits challenging the program. Ms. Brand wrote that while the legal question was “difficult,” the government’s legal theory was “at least a reasonable reading, made in good faith by numerous officials in two administrations of different parties.” *

Did the government have a "reasonable reading" of the law?

Let's set aside the issue of whether the phone dragnet violates the Fourth Amendment and ask whether the program is in keeping with Section 215 of the Patriot Act. Representative James Sensenbrenner, one of the Patriot Act's authors, says:

When it was reauthorized in 2006, Congress sought to limit the government’s warrantless access to records. Under the revised law, the government can obtain records if a court determines they are relevant to an authorized investigation into international terrorism or foreign spying. But in a secret policy decision handed down by a secret court, the government reinterpreted the relevance requirement as an expansion of power rather than a limitation. How can every call that every American makes be relevant? The answer is: They can’t. At a hearing before the House Judiciary Committee, FBI Director Robert Mueller argued that the administration’s request for all foreign and domestic phone records was relevant because the database of all those calls includes relevant information. This expansive characterization of relevance makes a mockery of the legal standard. According to the administration, everything is relevant provided something is relevant. Congress intended the standard to mean what it says: The records requested must be reasonably believed to be associated with international terrorism or spying. To argue otherwise renders the standard meaningless. **

The government's argument seems un-reasonable to me too. And I confess that I have a hard time believing it was made in good faith. "The program began in late 2001 based on wartime authority claimed by President Bush," the Times reminds us. "In 2006, the Bush administration persuaded the surveillance court to begin authorizing the program based on the Patriot Act under a theory the Obama administration would later embrace." If there's ever a time to suspect bad faith, isn't it when a program begins with no legislative justification, persists that way until it strikes people as lawless, and is only subsequently said to be covered by an existing statute, which is reinterpreted for the purpose?