Barry Ritholtz nicely summarizes the monopolist’s modus operandi:

Microsoft has a monopoly on the desktop — and because of that, there are certain behaviors they are legally restricted from engaging in (at least, in legal theory). Microsoft should not be able to disadvantage competitors by leveraging that monopoly in a way that restricts competition.
Search is a perfect example: By setting the default to MSN search, and making it extremely awkward to change it, they automatically become one of the top 3 players in that space. What would take any other company billions of dollars to do, they get for, oh, about nothing.

Clearly, in the case of newspapers, protected by the Newspaper Preservation Act of 1970, it’s rather simple to create additional print publications, that for others would be expensive. Similarily, they can use this monopoly postion to give away advertising products & content, if necessary, to kill competition (just like Microsoft gave away Internet Explorer, to “cut off Netscape’s air supply“).