Mary Whitehouse would be proud: the UK's 9pm television watershed is 50 years old. But the cut-off point for grown-up TV that we've all grown up with is in danger of becoming irrelevant in our brave new world of online and on-demand viewing.
In July 1964, Parliament passed the law banishing harmful or offensive television programming to later in the evening so as not to corrupt the delicate sensitivities of the nation's young folk.
Nine o'clock has long marked the latest point at which kids are banished to bed so parents can get on with watching gratuitous sex and violence in peace. Programmes rated 15 or above cannot be shown between 9pm and 6am the following morning, with 18-rated content held back until 10pm to mark a gentle transition in case any youngsters manage to squeeze a few extra minutes in front of the telly. The rules apply to adverts as well.
There are some exceptions for different types of channel: premium or pay-per-view services are allowed to start the watershed at 8pm, while PIN-protected channels such as Sky Movies can show adult content at any time.
The watershed hasn't always been entirely watertight, however. From the Sex Pistols turning the air blue on a talk show in 1976 to Shaun Ryder doing the same on "TFI Friday" in 1996; and Christina Aguilera, Rihanna or Lady Gaga gyrating on "The X Factor", every now and then something will creep through that challenges notions of what's acceptable for kids to see.
'Five more minutes, mum, pleeeeease?'
The watershed is now enforced by broadcasting and communications regulator Ofcom. In its latest research, Ofcom checked with the nation to find if the watershed is still relevant and appropriate. The results show that a large majority of viewers still support the TV watershed, with eight out of 10 parents happy the cut-off is at the right time.
Back when live telly was the only way of viewing, the watershed was an elegant way of protecting children from adult content. But the changes in the way we view films and television in our homes over the ensuing decades have complicated matters.
Videos and later DVDs are rated and have the physical barrier that a child cannot usually get them from a shop, but online and on-demand services don't have that physical requirement. The rise of on-demand viewing and downloading of films and TV shows makes it harder to protect children, with many online services simply requiring you to click a button promising you are indeed of a suitable age -- scout's honour, cross your heart and hope to die -- to view the content in question.
"Watching films and programmes online is as normal to young people as viewing on a TV set," says Tony Neate, CEO of Get Safe Online, "and this can present a huge challenge for parents trying to make sure that what their children are watching is age-appropriate."
"We need to be realistic and accept that kids are always going to be intrigued by content produced for an older audience," says Neate, "so parents should as far as they can keep a close eye on online viewing habits. Technology can never replace a good talking relationship, but parents should also consider parental controls that limit what content is viewed and the times when they can use the internet."
You can protect children from viewing adult or harmful content online by setting up parental controls on browsers and search engines, and on your TV, mobile devices and within apps. Check with your broadband provider or your TV provider to find out what parental controls they offer, or click the links on the left for more help and advice.