How does Shakespeare's Much Ado About Nothing challenge us to be more critical of how we "know" what we "know"?

In many of Shakespeare's plays, the themes of miscommunication or delayed information play prominent roles. In this comedy in particular, the harmful role of gossip compounds the more general problem of miscommunication. Ultimately, it is revealed that people have gotten all worked up over nothing. But for the characters affected during the action, it certainly does not seem like that is where things are headed.
One key piece of "knowledge" (that is basically gossip) is the idea that Beatrice secretly loves Benedick, and vice versa. Claudio and Hero set up this confusion. Once they have this "knowledge," the "lovers" start to act accordingly.
While this fabricated romance actually turns out well, the negative consequences of false knowledge tear apart Claudio and Don Pedro through the evil gossip Don John spreads. Equally harmed is Hero, whose reputation seems damaged beyond repair. Although she is proved virtuous to Claudio at the last minute, it is clear that Shakespeare is driving home a key point: don't believe everything you hear.