Several Hollywood stars including Jennifer Aniston, George Clooney, Miley Cyrus and Drew Barrymore have waged a war against social networking websites. As Facebook registered its 500 millionth member, the celebrities fear the growing link to sex crimes against children and underage abductions, Daily Express reported.

In one high-profile case in the US, a 48-year-old man allegedly kidnapped a 13-year-old girl after lying about his age online and asking her to go out on a 'date'.

"I'm urging kids, don't go on the Internet. It's not fun; it's dangerous," said teen sensation Miley Cyrus, a former 'web addict'.

Some of the celebrities are also enraged over bogus home pages in their names.

"I would rather have a prostate exam on live television by a guy with very cold hands than have a Facebook page," said Clooney.