But, but, but...
For someone to be a risk to my child that person must be in the same physical location as my child. True, yes?
So that means there are 2 possibilities.
Either the paedophile lives or works near enough to us that s/he has seen my child in real life and fixated on my child. In which case the paedophile will already have the means to find my child through conventional routes - yes, s/he might also find photos on the Internet, but those photos aren't the driver behind the paedophile's obsession; nor do they put my child at any greater risk.
Or this hypothetical pedophile has no real life interaction with my child but has simply stumbled across my child's photo on the Internet somehow. In which case s/he has to identify my child then identify my child's relationship to either me or my husband then find our address then visit our address to find out our routines and only then create a plan to start interacting with us so as to harm my child.
In the meantime, statistically many more paedophiles's lives will have intersected with ours just through day-to-day living. On the street, at the shops, on the bus, at school - so many other possibilities.
So there simply isn't a mechanism whereby photos on the internet put a child at greater risk than already exists.
The man accused of taking poor little April Jones lived in her community. I bet you all the money in my pocket against all the money in yours that (if he is guilty) then he could have got her photo in a million other ways, and probably did. And I bet you all the money in my bank account that he didn't first become fixated on her through Internet photos.
None of this negates the importance of being internet-safe, of course it doesn't. But a few random photos of a wedding, presumably not tagged as "Bride and XX, aged 3, of 55 Acacia Avenue, Snatchville, whose parents don't keep a close enough eye on her at a wedding to realise she's being photographed so might be worth a punt with this one"? No. Worrying about this aspect detracts from where the real risks lie. Those are very much around much older children with their own Internet access - grooming, they themselves posting deeply inappropriate photos, their emails going viral, etc etc.
Obviously, there are some circumstances, already mentioned here, where greater care is needed in respect of images of small children - adoption, previous abuse, their parent's occupations putting the children at risk of retaliation - but even in those very valid cases, the source of the harm is not the photos themselves but rather the individuals already looking to do harm to that family specifically because of existing real life interactions.
I've got more time for the argument that our children don't have any input into whether their image should be posted on the Internet because, once it's there it's there forever. But in truth the vast, vast majority of shots of children are not in any way embarrassing or inappropriate, or capable of leading to the child being identified as an adult.