The acting deputy secretary of homeland security warned employees Saturday that “there may be a heightened threat” against them, according to a memo obtained by CBS News. The warning comes amid the increasing furor over the Trump administration’s “zero tolerance” immigration policy.

“This assessment is based on specific and credible threats that have been levied against certain DHS employees and a sharp increase in the overall number of general threats against DHS employees — although the veracity of each threat varies,” says the message from Claire M. Grady. “In addition, over the last few days, thousands of employees have had their personally identifiable information publically [sic] released on social media.”