Despite the latest in filters, children can still find everything on the internet, from nudity to sites featuring violent sex acts.

"Kids are exposed to pornography at incredibly early ages, when their brains are going through profound developmental changes," says Philadelphia psychologist Michael Bradley. "This has caught parents off guard. (Porn) has always been there, but it's always been in a lower volume."

In recent years, he says, "It's been like a tidal wave that has swept over kids."

Questions emerged with the news that search giant Google is fighting a Justice Department subpoena for its search data. The case is part of the Bush administration's legal fight to defend the polarizing Child Online Protection Act of 1998. The measure would make it a federal crime for a commercial website to put up materials "harmful to minors" unless placed in areas only accessible to adults.

Regardless of where they stand on the law, experts agree that parents need to take matters into their own hands ...