Peggy Noonan blogs for the Wall Street Journal about California Sen. Dianne Feinstein’s recent accusations of nefarious CIA activity.

Today’s case: Sen. Dianne Feinstein has accused the CIA of compromising and trifling with computers being used by Senate staffers in an investigation of the agency. …

What is startling in the story is that it’s not surprising. The CIA is under Senate investigation, in this case regarding its now-defunct secret interrogation and detention program. You can argue whether the investigation is or is not historically justified, politically motivated or operating fully on the up and up. (Unnamed CIA officials had previously told the Washington Post that, in fact, Senate investigators had themselves accessed documents to which they were not entitled.) Feinstein is suggesting the CIA, an executive agency, used its technological capabilities to thwart, confuse or disrupt the legal investigative actions of the legislative branch. If she is correct, that would be a violation of the laws preventing the CIA from conducting domestic surveillance. And of course it would constitute a violation of the separation of powers.

But again, it’s not surprising. If it is true it is very bad, but not a shock. We have been here before, as Ron Fournier notes. But this story will likely make a difference, and wake some people up on the Hill. Dianne Feinstein of California has been a U.S. senator for more than 21 years and has been a vocal defender of the U.S. surveillance apparatus since it came under attack with the emergence of Edward Snowden. She views surveillance from a national-security perspective. As chairman, for five years, of the Senate Intelligence Committee she is more aware than most of the security threats and challenges under which America operates. There is a sense she has viewed the alarms and warnings of antisurveillance forces as the yips and yaps of kids who aren’t aware of the brute realities she hears about in classified briefings. Over the past decades she has been exposed to a large number of intelligence professionals who are first rate, America-loving and full of integrity, and so worthy of reflexive respect. Her loyalty would be earned and understandable.

But now she, or rather her committee’s investigators, have, she believes, been spied upon. Which would focus the mind. She is probably about to come in for a great deal of derision. She should instead be welcomed into the growing group of those concerned about the actions and abilities of the surveillance state.