YouTube is doing its part to prevent the Internet rearing a generation of hyper-violent, depraved fiends by rolling out a Safety Mode that blocks access to 'potentially objectionable' content.
A link now appears at the bottom of every YouTube page, telling you whether Safety Mode is on or off. If you click the link and turn Safety Mode on, it'll stay on, until little Jimmy comes along, turns it off and searches for 'boobs' or some such unspeakable filth. To prevent the little rascal having his inquisitive way, you can log into your YouTube account and lock your choice for the browser, so everyone who uses it subsequently must kowtow to your fascist censorship. Take that, Jimmy!
Note that your choice is specific to the browser you make it in. So if your sweet little tyke favours Chrome over Firefox and you haven't turned Safety Mode on for every browser under the Sun, said rapscallion may still quaff deep from the tankard of unseemliness.
Also worth remembering is that surfing in porn mode anonymous browsing circumvents the Safety Mode lock. The best way to prevent a wily youngster from taking advantage of this is to threaten to chop their hands off if you catch them at it.
Safety Mode also hides all user comments by default. You can reveal them, if you're in dire need of an idiocy injection, but offensive words will be starred out. Safety Mode might be worth turning on for this feature alone, frankly.
We tried a variety of rude search terms, including perennial favourite 'John Prescott naked, smeared in butter', and Safety Mode worked fairly well. YouTube stressed in its official blog that this mode isn't 100 per cent effective though, and that tallies with our experience. Be careful out there, people.