It’s true, as a public school employee you are protected from unreasonable searches of your workplace, but that doesn’t mean that anything you leave in plain view on your school-owned desk or file cabinet—or anything saved on your school computer—is off limits to administrators. Administrators can inspect school-owned property at their discretion, and have done just that, including searching computers for emails and other information.
And that’s not the only thing. While the purse, messenger bag, or briefcase that you bring to your classroom or worksite is considered private property when you are at work, the administration can search them if there’s reasonable suspicion that there’s an item inside that violates the law or school policy. MSEA Dispatch
BOTTOM LINE? Be aware ... don’t store personal items in a school-issued desk or file cabinet. And maybe most important, never use your school-issued computer.