captcha became user friendly but if that is what you fear then we can reverse the mechanism meaning instead of trying to type what is unreadable, we write it down like a pass that will be used everytime we upvote ... a 1 time "reverse" captcha will be used to register ur upvote pass...
how you define greedy lol... u can only prevent abuse by ...

reverse captcha - reversing abuse
reverse "catcha" - catcha ur greedy bottom
lol
talk to me baby.. :p