The censure you refer to initially in your post may be based on the reasonable concerns held by persons in authority for child safety arising from their exploitation by pedophiles who are well know to be engaged in exchanging photos of children through networks.
That's not to say all people who like looking at kids playing or taking photos have ulterior motives. Far from it. Most normal people have a great affection for kids, but may not be able to express it because they have no kids of their own or their kids are grown up and left home. They may take photos partly out of this liking or in remembrance of their own halcyon days. My late father was a great favourite with all the kids of the neighbourhood wherever he lived, with his ready smile and a kind word. There are photographers who specialise in taking photos of children. We all need to be reminded of our lost innocence and vulnerability from time to time.
Its a (relatively) free country and to the best of my knowledge you cannot stop people taking photos in public places. If however people are taking photos of kids in public places and you are concerned, then you could consider either approaching them and asking them to stop or reporting them to the local Gardaí.
I have traversed the above to give a bit of background to a subject which can easily touch off knee jerk reactions if presented out of the blue. If you're going to photograph kids - for whatever reason - you should advertise the context before the event. I would be very wary of taking photos of kids playing in derelict houses that are not in the public domain - or even 'escaping' from the houses. Irish people have an almost pathological dislike of surveillance of any kind, even when -as with speed cameras - its for their own good.
In terms of advertising the context, photographs of this nature should only be done with the knowledge and agreement of all stakeholders. This starts with the owner of the building asking you to do this, and notifying the Gardaí, but should also include alerting the parents of the kids if they are resident locally and the Gardaí can help with this as can your local residents association.
Quite apart fom any 'pedophile photographer' allegation that may surface agaisnt you, there is the whole issue of "fair play" - you cannot be seem to be going out of your way to criminalise children. Kids like to play in old houses. God knows I played in ehough of them myself and enjoyed many a happy hour playing detective and historical investigator / explorer. I agree that when it degenerates into vandalism it must stop, but there are stages to progress before you get to taking surveillance photographs.
The obvious approaches to the local residents association and from there to the Gardaí and parents should be tried first.
If you're not acting on behalf of the property manager and at his request, specifically if you are not getting paid to do this and have not cleared it with the Gardaí and made it known in the local community, you could attract unwholesome allegations and possible claims against you. Baseless though these may be, the making fo the claim alone could cause you great personal upset and embarrassment.
So my best advice is, unless you've asked to do this professionally - and you may well need specialist equipment for night shots, etc. - and are leaving a wide trail of who you are and why you're doing this - don't do it.
ONQ.
All advice on AAM is remote from the situation and cannot be relied upon as a defence or support - in and of itself - should legal action be taken.
Competent legal and building professionals should be asked to advise in Real Life with rights to inspect and issue reports on the matters at hand.