Let's wait to see what the "suspicious devices" are first. A few years back "bomb making materials" were found near here. It turned out to be a gallon of gas in the back of a pickup and a bic lighter on the seat. Thank you BATF.
The bomb squad already blew one up.
Also, there was the "Portland 7" - a group of suspected terrorists that were arrested. Salem is only 45 minutes south of Portland.
Having said that, the feeling around here is that it's a lone, disgruntled nut.