Warning - beware of people
Now here's a useful warning. In response to the Russian school terrorist attack, the government is advising people to be on the lookout for:
Interest in obtaining site plans for schools, bus routes and attendance listsHas anyone ever asked for any of these things anywhere? This seems highly unlikely
Prolonged "static surveillance" by people disguised as panhandlers, shoe shiners, newspaper or flower vendors or street sweepers not previously seen in the areaSo now we expect teachers to make out terrorists on the street disguised as flower vendors. This makes sense. It's what they're trained to do.
Observations of security drillsLook he's staring - whoops now he's looking away. So if you look at - or don't look at them, it's suspicious? That about covers it.
People staring at or quickly looking away from employees or vehicles as they enter or leave parking areas
Foot surveillance of campuses involving individuals working togetherThat would be groups. So if you see any people walking around, alone or in groups, looking at you or not, call the feds. That's a great warning.