Federal investigators may soon be authorized to search a job candidate’s social media postings when deciding whether to issue a security clearance.

Director of Intelligence James Clapper signed a policy Thursday allowing background check investigators to scan public social media postings as part of their assessment. The policy was signed in advance of a House Oversight and Government Reform committee hearing Friday morning.

In the past, clearance investigations have involved interviews with the candidate’s friends and family.

“Today, with more than a billion individuals on Facebook, what a person says and does on social media can often give a better insight on who they really are,” Rep. Mark Meadows, R-N.C., and chair of the subcommittee on government operations, said during the hearing.

During the hearing, lawmakers pushed officials to explain the mechanics of an Office of Personnel Management and Office of the Director of National Intelligence pilot that plans to incorporate an automated search of social media platforms into the background check process. In April, OPM began gathering information about companies that can provide social media tracking services.

For instance, will the system be able to identify an individual based on their online postings, even if they’re writing under a pseudonym? Rep. Ron DeSantis, R-Fla., noted that Booz Allen contractor Edward Snowden contributed to online forums under a consistent username before he revealed classified information about the National Security Agency’s tracking practices. Knowledge of that username may have alerted authorities he could be an insider threat, he said.

A social media search tool wouldn’t have caught those posts because they’re not public, said Bill Evanina, director of National Counterintelligence and Security Center at ODNI. And ODNI isn’t planning to ask individuals to disclose their alternative online personal activities, he added.

OPM is examining which aspects of the social media search should be automated and where human intervention is necessary, Beth Cobert, acting director at OPM, said. One crucial task is verifying the identity of a social media poster, especially when the individual has a common name.

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Still, some questions about the extent of these social media searches remained unanswered. Rep. Gerry Connolly, D-Va., said he was concerned about the implications for “third parties that happen to engage with the applicant that have not consented to waive their privacy rights.”

The policy comes shortly after Twitter denied government agencies access to Dataminr, a data service that scans all existing tweets for trends.