Well, gricers have no business being anywhere the public isn't allowed to be fair without official permission or supervision. Not on a modern rail way operating at high speeds. Have heard of photographers/phone photographers doing really stupid things to get that Instagram cool pic, sometimes literally on IR metals. The past is a different planet, I don't think we should tolerate gricers swarming all over per way like they did in days of yore. If you saw the photos of the Buttevant aftermath with public wandering and gawking around cranes and lifting gear, no one in their right mind would think that's ok now, but par for the course back then.
Don't think people could have been that bothered reporting them, even if someone did, by the time the law came out they would be long gone.
There was a near miss with a few graffiti lads a couple of years ago, they are lucky to be still in the land of the living. For what it's worth the law isn't taking these offences as seriously as they should. There's a bit of boys will be boys about it all.