Usually, the goal of PR professionals is getting people to talk about their latest project. But, occasionally, they just want people to shut up.

For weeks, anticipation has been building for the July 21 release of Harry Potter and the Deathly Hallows, the final book in the wildly popular series. Last week, someone calling himself Gabriel leaked what he claimed was the surprise ending, threatening to dampen that Potter excitement.

Thanks to the Web, information (and disinformation) runs non-stop, threatening to spoil ...