FBI Admits to Monitoring and Intercepting SnailMail?!

So I just came across this article at CityNews | Local News | Top Stories (of which there are 313 similar stories via googlenews ‘superbowl massacre’) which details some wacko’s plot to bring an assault rifle to the superbowl.

What struck me as odd was this part of the story:

“Kurt Havelock mailed a manifesto to local media outlets on Sunday vowing to “shed the blood of the innocent.” But authorities managed to intercept the letters and seized them before they made it out of the postal facilities.”

Can anyone explain a scenario in which this interception could legally and logistically occur?

http://seattletimes.nwsource.com/html/nationworld/2003508676_mail04.html
As to how it could occur, the guy calls in to the police and confesses, including to the letters he sent. Then there are three scenarios I can see playing out. (1) Police contact the news outlets and they allow the messages to be intercepted (unlikely), (2) Police call up the post office and seize the letters without a warrant (likely), and (3) Police get a warrant for the mail (unlikely). Legally speaking, (2) is illegal, but nothing is really going to come from it.

First of all the article says that they seized the letters, not open the letters or read the letters. Since the suspect was peeved and planning on filling a bunch of people with lead, a reasonable person might want the letters intercepted since they could contain a bomb or poison in addition to a rambling boring manifesto. Warrants are not always necessary in such cases as “hot pursuit” or where a crime is reasonably occurring (eg an officer is walking by a house and hears screaming and gun shots.) In any case obtaining a warrant to open and read the letters would certainly be helpful when the case goes to trial.

i see three scenarios -

  1. a news outlet received the letter and notified the authorities. The authorities then acted to protect the public by intercepting the remaining letters.

  2. The suspect confessed. The authorities then acted to protect the public by intercepting the remaining letters.

  3. In each post office there is a back room with a tea kettle. where all first class mail is diverted. An government agent carefully steams open each piece of mail and after reading it and after determining the threat level seals the letter back up. After finding the manifestos the authorities then acted to protect the public by intercepting the remaining letters.

They don’t call it snail mail for nothing.