It does. Here’s why. First, it is dangerous to have half a million people — the number of private contractors holding top-secret security clearances — peering into the lives of their fellow citizens. Contractors aren’t part of the chain of command at the N.S.A. or other agencies and aren’t subject to Congressional oversight. Officially, their only loyalty is to their company and its shareholders.

Second, with billions of dollars of government money sloshing around, and with contractors providing advice on how to spend it, conflicts of interest and corruption are inevitable. Contractors simply shouldn’t be in the business of managing large projects and providing procurement advice to intelligence agencies. Thomas A. Drake, one of the N.S.A. whistle-blowers who exposed the waste and fraud in the N.S.A.’s Trailblazer program — Mr. Hayden’s disastrous attempt to privatize the N.S.A.’s analysis of intercepted signals intelligence — estimates that the project cost taxpayers as much as $7 billion (it was canceled in 2006). Yet the contracts kept rolling in, and Mr. Hayden went on to head the C.I.A.

Third, we’ve allowed contractors to conduct our most secret and sensitive operations with virtually no oversight. This is true not only at the N.S.A. Contractors now work alongside the C.I.A. in covert operations (two of the Americans killed in Benghazi were C.I.A. contractors; we still don’t know who their employer was).

They also analyze imagery and intercepted intelligence to track and kill suspected terrorists for the United States Special Operations Command. In April, the Pentagon’s Office of Inspector General found that nine of 28 tasks outlined in a $231 million contract the command awarded “may have included inherently governmental duties.” In other words, contractors were involved in secret and highly sensitive operations that by law are reserved for government operatives. After Blackwater’s sordid history in Iraq, we don’t need more unaccountable actors fighting terrorism for profit.

Finally, there’s the revolving door — or what President Dwight D. Eisenhower called “undue influence.” With few regulations and no questions being asked on Capitol Hill, hundreds of former top N.S.A. and C.I.A. officials have migrated from government to the private sector and back again. The poster boy is Michael McConnell, who served as N.S.A. director during Bill Clinton’s first term, then went to Booz Allen for a 10-year stint, became director of national intelligence for George W. Bush from 2007 to 2009, and is back at Booz Allen today.

We have no way of knowing how people like Mr. McConnell formed their business relationships, and what agreements or compromises they might have made to get their private-sector jobs (and vice versa). They may be honorable men, but as recent history has shown us, there’s no reason to take them at their word. And the current one-year ban on lobbying for former officials does little to prevent conflicts of interest.

Congress must act now to re-establish a government-run intelligence service operating with proper oversight. The first step is to appoint an independent review board — with no contractors on it — to decide where the line for government work should be drawn. The best response to the Snowden affair is to reduce the size of our private intelligence army and make contract spying a thing of the past. Our democracy depends on it.