At Google, a seemingly innocuous action can earn an employee the attention of the company’s corporate security department.

For example, when Google wants to find out who has been accessing or leaking sensitive corporate information, the company often homes in on employees who are thinking about leaving it. In the past, its security teams have flagged employees who search an internal website listing the cost of COBRA health insurance—which gives workers a way to continue their coverage after leaving their employer—for further investigation, according to a person with direct knowledge of its tactics. Employees who draft resignation letters or seek out internal checklists that help workers plan their departures from Google have also faced similar scrutiny, the person said.

It has even looked at who has taken screenshots on work devices while running encrypted messaging services at the same time, according to current and former employees with knowledge of the practices. Bulk transfers of data onto USB storage devices and use of third-party online storage services can also raise eyebrows among Google’s security staff.