well there's a double catch here....
It is possible to clip without hearing the effects. It ends up being a squared off waveform, more than likely as a result of some type of brickwall limiting. Up until about the early to mid 90s, it was unheard of to take it that loud.
Now it's the norm for reasons that are debatable..
Some processors do it better than others, but it's still achieving the same thing. Then of course there's the clipping with the horrid popping and clicking.
The complete shit job if you will.
The U2 thing isn't a surprise really, I mean the loudness war has been going on for a while now. Technology is at the point where we can smash things and somehow it comes out somewhat listenable.
Bob Ludwig talks at great length about the epidemic of smashing things in order to bring them up in apparent loudness. However, you lose tons of dynamic range when you do that. You can also lose punch, transparency, transient information (like snares, toms, kick, etc).
But that of course comes to the mastering stage. I should never mean that you're smashing things prior to that. Most mix engineers don't really have the right setup and experience to pull that off. If you'd want to address that question for the mastering engineer, then he/she should be able to feed your curiousity better.
In my honest opinion, I see it as a false high with alot of work out there. You can smash the song all you want, and it may sound all badass in the moment, on a few sets of speakers.
However, in the long run you find out that it's restricted, it's just too much pushed upfront, it's hard yet unrelenting in weakness.
It's like trying to play B-ball in a room with 8ft high ceilings.