Ok, I don't understand this. It sounds to me like you're more interested in the act of vandalism (minor though it might be) than you are anything to do with pedestrian safety. In fact, what kind of a road is it? What's the speed limit on it? What I'm getting at is ... how do you know it will have any effect whatsoever on pedestrian safety? Are you going to put up signs to motorists, too? And it may not be minor. What if it gives some little kid a false sense of security and he crosses when he shouldn't, and gets killed? I don't know what the circumstances are there, but I'm just saying have you really thought this through? And what does this have to do with "standing up to the man"? You really think splattering some paint on the road is going to do anything to "the man"? Surely you're not that naive. And finally, you'll get caught. They can trace the paint. You'll leave DNA. You'll leave footprints. You'll do something wrong. If they consider it important enough, they'll find you.
Pandas eat shoots everybody knows that, there's no need for a comma. That was the sweetest grammar Nazi correction even though, sweet like chocolate.
As for the topic, a jobsworth might say something like, "you endangered the lives of children as there is no warning signs or lights for the approaching traffic" then you could get prosecuted for reckless endangerment. I mean if you took a template down with you to spray on the rectangles you'd be over and done in about a minute tops, but hey, what if you actually DID kill a kid because some sleeping loser was texting on their phone and didn't see the stripes? There's no need to do it this way, the local government will fall all over you if you contact your local civil community group and campaign for this. They love ruining the rest of our lives to improve "safety". And hey if it really DOES need a crossing, then that goes doubly.