WaPo:

...all 180,000 employees and contractors are being required to sign the three-page forms as part of working for the agency...

...congressional critics and government watchdog organizations such as the Federation of American Scientists call the policy a potentially precedent-setting expansion of official secrecy whose provisions are overly broad and unworkable, if not unconstitutional.

Ken Johnson, spokesman for House Homeland Security Committee Chairman Christopher Cox (R-Calif.), said GOP aides have been approached by DHS officials as a group and individually. One junior aide contacted directly signed the agreement, but his supervisors and Cox repudiated it as soon as they found out.

"We have steadfastly refused to sign any nondisclosure agreements. From our perspective it would be inappropriate, and at the very least unnecessary," Johnson said. "This is unclassified material and Congress has a right to it without signing away our lives."

Democratic staff also refused to sign nondisclosure agreements, minority committee spokeswoman Moira Whelan said.

"They're forgetting who's overseeing who," another panel official said...

See also the earlier "Border Patrol agents fear coming retribution".