(CNN) US Customs and Border Protection is now considered a "security agency," a move that allows the agency to shield information about personnel from the public.

The move has raised concerns among lawyers and advocates of government transparency, who say the agency will be further shrouded in secrecy.

Acting CBP Commissioner Mark Morgan announced the change last Friday in a memo to staff, according to a CBP spokesperson.

The change in designation, which took effect January 31, adds a layer of secrecy to the border agency -- which falls under the Department of Homeland Security -- at a time when it's been under increased scrutiny. It puts the agency under the same designation as law enforcement agencies like the FBI and the Secret Service, but it doesn't appear to increase the agency's authority.

A spokesperson told CNN in a statement that the catalyst for the change dates back to last summer, when CBP and the Department of Homeland Security learned of a Twitter account posting employee information that is available through the Office of Personnel Management, an agency that manages federal employee information, including salaries. The information posted on Twitter was considered by the Office of Personnel Management to be public information, and is available through several federal employee salary database search websites, the spokesperson added.

The spokesperson said CBP leadership advocated for the change with the Office of Personnel Management. Anthony Marucci, communications director at the Office of Personnel Management, confirmed the redesignation, which was first reported by The Nation.

"Out of concern for the safety of our workforce, CBP leadership advocated for and recently received OPM's agreement to designate CBP as a Security Agency, protecting CBP employee's information from OPM's disclosure policy," the CBP spokesperson said. "Previously, only CBP's frontline law enforcement, investigative, or intelligence positions held this designation. The new designation protects the entirety of CBP's workforce."

One of the implications of the change is that information that might usually be made public could be redacted in Freedom of Information Act requests, sparking concerns among lawyers and advocates, who worry that it could shield personnel from being held accountable for wrongdoing.

The CBP spokesperson reiterated that the new designation is intended to protect employees -- such as contracting officers, human resources and import specialists, among others -- from situations like last year's posting.

The Freedom of Information Act compels the government to hand over documents and, while those documents are often redacted, the new designation allows CBP to exclude more information than it did before.

"One thing we find in FOIA responses is agency employees breaking the law or doing the wrong thing. Sometimes we can identify them because their name is on the email," said Matthew Hoppock, an immigration lawyer. "Now we may be getting FOIA responses showing people breaking the law but we don't know who they are."

Clark Pettig, communications director at American Oversight, agreed and noted that other agencies, like the Education Department, can use an exemption in FOIA to withhold information. Redesignating an agency as a "security agency" essentially bolsters the argument to redact a name, for example.

Pettig also said in an email that he understood there may be "valid security reasons" to withhold certain CBP employees' information, however, this designation "creates significant potential for abuse by an already secretive agency with a poor track record of public transparency."

"CBP is at the center of some of this administration's most troubled and troubling policies, from the border wall to 'remain in Mexico,' and giving them one more excuse to withhold information from the public is the last thing we should be doing right now," Pettig added.