Red Lights

Since when did stop lights become stop signs or 'proceed with caution' when they are red?

In the last week or so, I've come across two occassions where this has happened.
One day, a car stopped at the light, then went even though it was still red for them. I don't even think they were phased by it, didn't realize that it was in fact a red light.
Another day, an SUV didn't even stop at a red light. I think they slowed down, saw that no one was coming and just went. Not sure if they noticed that it was a red light, or just didn't care.  Probably the latter.

There is a reason red lights exist. For the safety of drivers. Apparently ppl don't understand that concept...