Google's executive chairman has spoken out about the privacy battle that is waging online every day, in which commenters could be held accountable for their ill-thought-out postings and tweets long after their initial reactions subside. He also pleaded for parents to educate their children about online safety and privacy, suggesting that such a talk is more important than the "birds and bees".

Speaking on Reuter's online TV channel during the Politics Aside conference in California, and reported on Forbes, Schmidt said that while a child's criminal record is wiped when they turn 18 - in the US, at least - what they post online can haunt them forever. "It’s going to follow you for the rest of your life," he said.

He also warned against just blurting out private matters online without think of the consequences. "We need to fight for our privacy or we will lose it," he said. "[User generated material] is a privacy nightmare especially if you’re 15."

And it is up to parents to ensure their children are fully aware of the dangers and responsibilities. "I'd argue for those of you with teenagers and pre-teens, you should probably have the online talk before the sex talk with your kids," Schmidt said.

"There is no delete button on the internet and it’s easy to lose your privacy."