Yep.. you can.. on the oversoul level some people know your thinking about them too.. but more than that in LOA if your thinking about someone.. you may observe telepathy or instant manifestation.. meaning they call you etc..
While I don't have it all understood.. one of the things my teacher says is.. that all of life is a mirror.. so if you think good thoughts about someone.. your thinking good thoughts about yourself too.. and it's a reverse effect too.. if your thinking hate about someone.. you lower yourself to their level..
There are energy healers in our society.. that transmit energy even anonymously to help people.. really.. heal themselves.. if you wish I can dig up some exact info (not paraphrased) on this subject.. if I have some
Understand though that all of life is free choice.. so just cause you lead by example.. or wish the best for someone.. doesn't mean they have to choose that.. but that is the only real way you can influence people..