...spotted on his return from having a cup of coffee that someone had smashed in the window of his car, parked in the centre of Oulu.
      The Apple PowerBook computer that had been on floor between the front and back seat was no longer there. ...

He was wrong. Things didn't turn out quite that way. One of Päivärinta's friends started a thread about the theft on a message board - one mainly devoted to computer-related matters and to "things Apple" in particular. The board's name is Hopeinen omena: "Silver Apple", after the Apple logo.
One week after the theft, on March 27th, a board member using the login handle bbin reported on the same thread that a notebook computer answering the description

  Martti Tiainen from Tuusula, another subscriber on the Hopeinen omena forum, sent the seller a message on Huuto.net, offering EUR 200 more than the highest bid that had been received. The original highest bidder, who was acting in perfectly good faith, did not wish to get involved in the matter, so a new "buyer" had to be found.
      The EUR 200 was tempting enough. The seller took the bait.

      Tiainen and Päivärinta met for the first time IRL (in real life, as the saying goes) when they both arrived at the main railway station in Helsinki immediately before the planned encounter with the seller.
     
"I had already called the police to get their input on how we should act in this situation. The police in Helsinki said to call them when we had the guy", recalls Päivärinta.
      They had "back-up" in the form of four railway station security guards whom they told about the stolen computer.
      Tiainen went alone to meet the seller in a restaurant. The others waited downstairs.
      The seller, who appeared quite relaxed, agreed to open up the machine, at which point Tiainen saw the serial number, and was able to confirm that the Apple belonged to Päivärinta.
     
He then gave a signal to Päivärinta and the four security men, who appeared as if from nowhere and surrounded the seller. Päivärinta introduced himself as the real owner of the stolen computer.
      "Oh Yeah? Sure, sure", offered the seller, possibly wondering how a transaction that was going down 600 kilometres from Oulu had taken such a strange turn.
      After a while, the police arrived, and took both the seller and the computer to the Helsinki Police Department HQ in Pasila. Päivärinta got his PowerBook back two days later.