Last week, as part of my job, it was my misfortune to be immersed in the depraved world of Vanessa George, the nursery worker who, along with her two co-accused at Bristol Crown Court, admitted to a sickening catalogue of abuse against children she'd been trusted to look after.

This case is deeply troubling on so many levels. Firstly, that two of the three involved were women and mothers themselves.

That this vile trio only set eyes on each other for the first time in court, that they stumbled across each other on Facebook, a networking site used by so many of our children. And that Vanessa George had undergone the usual Criminal Records Bureau check that all those who look after our kids have to undergo.

On this evidence the CRB check provides us with very limited protection.

But of course the most terrible part of this macabre story is the wrecked lives that George and her accomplices have left in their wake, particularly the parents of the children at that Plymouth nursery.

Parents who can't be sure whether their little ones were among her victims and, even if that information became available, are torn as to whether they really want to know. What's more they are almost certainly struggling to cope with guilt, prompted by the fact that by dropping their children off every morning, they were effectively delivering them to the devil.

The devil disguised with a smile and a nursery worker's uniform. There but for the grace of God goes every single parent reading this who has used a nursery.

So what practical and immediate steps can be taken to ensure we're not reading about another Vanessa George in a couple of years' time? Already it's been suggested that staff mobile phones are left at the front door of every nursery. Maybe nursery workers should be banned from spending time alone, behind a closed door, with any child.

Well, hopefully these and many other measures are being discussed up and down the country today and whatever guidelines follow the George case will at least reduce the risk of any repetition of what happened at Little Ted's nursery.

But is there anything all of us can do right now? Well maybe. Again the role of the internet has come under scrutiny and this case should make us even more aware of its corruptive power.

I spoke to Michelle Elliot, the child psychologist from Kidscape, who explained how George would inevitably have been encouraged by her accomplices. How, even if she knew what she was doing was very wrong, if someone online was telling her that her extreme behaviour was acceptable then that would have given her the confidence to continue.

It might even have pushed her further. There are dark anonymous corners of the web where people explore their sick fantasies and are encouraged to do so by others.

That encouragement acts as an endorsement.

There is also an implicit protection in online anonymity, which in itself can break the shackles of conformity.

It is vital that our children understand this, not in the context of what George was up to of course, but just so they don't grow up with a naïve acceptance of everything they stumble across on the internet.

They must understand that not everybody is who they say they are and that the rules of acceptable behaviour apply online as much as they do elsewhere.

Above all we must tell them never to use their invisibility as a licence to push the boundaries, because it may take them somewhere they really don't want to go.