Child behavior- kicking

Just a kid I know, Just curious. How would you guys handle a 2 and a half
year old child (boy) who kicks? Like, he will just walk up and haul off and
kick someone, and his parents do not say or do anything to him? He kicked
one of his grandparents, who promptly spanked him, and it made the parents
angry at the grandparent.

I don't believe it is ok for someone to spank another person's child if the
parent does not want them to. I am not a big believer in spanking but I do
think I would spank R. for something major and intentional, and where safety
is concern such as if she runs to the street when told not to etc. Of
course, I will watch her and not let her run around unsupervised anyway. But
when she is older I won't be able to watch her 24/7.

But I am telling you, if this kid had kicked *me* (it's a relative), I think
I would have spanked him too. He is out of control.

Opinions? Discipline that would work when "time out" is a joke? "Time out"
does not work for every kid although I know a 3 year old boy who finds time
out to be the WORST punishment ever, and will do anything to avoid it. lol.