Pop quiz you camera hotshots... what causes this? :)

This is a rental camera that I just got back in from a client, as you'll see in the pictures, there are these weird red pixels all over it. They aren't hot pixels, don't fade in and out, don't change with any other factor, lens or aperture or shutter speed - the effect is permanent, visible in both the LCD screen live and obviously in the footage... Camera is a 5Dmk2

The first image is around a 50% crop, the second is 100%

What do you think caused this?

The only thing I have heard of so far that can cause this are laserbeams that are used at venues, music festivals etc

I would say lasers as well... sucks.

Friggin' Lazzzers I would bet on as well. :(

Yep! that's lasers for sure ... blame the DJ who was using them ...I always play safe at events and make sure my back is up against the DJ desk so the lasers are going away from me but that still is no guarantee as the beams can also bounce off mirrors or anything shiny and ruin a sensor.

That will cost you a new sensor from Canon!!! As it's a rental camera however I would have a clause in the rental contract to charge the client if they use the camera to film lasers ... worth telling them too - "If you film any laser activity it's gonna cost you BIG money"

Yup, I know of an event in Seattle recently that had rental HDX900s and an EX3 pointing at concert lasers. Bill them big time.

This is why even if the beam is being split, avoid pointing CMOS cameras at lasers.

Yep! that's lasers for sure ... blame the DJ who was using them ...I always play safe at events and make sure my back is up against the DJ desk so the lasers are going away from me but that still is no guarantee as the beams can also bounce off mirrors or anything shiny and ruin a sensor.
At such events I'd be a bit more worried about my eyes than camera sensors after seeing that....... !

We have serious legislation about scanning the audience with lasers, is this not the same in the US?

Serious? Legislation? US?

Pick any two and it might make sense.

I think we are about to legalize laser armed event drones here in the US. :-)

Paul