can yahoo use this method to stop bots from entering Chatrooms??

I know yahoo has put in work to stop people from creating bots but even if this attempt is sucessfull theres still thousands or posibly millions that are already created,they use that thing when you have to type back the word in the block when creating and id which i think is very smart but they do this when creating ID's,what they need to do is keep them out of the chatrooms (the already created ones that is)they should put up A word code on the screen whenever you try to enter a chat,you have to type back that code,bots cannot read so they wouldnt be able to enter the code,the words needs to be put up in a format that cannot be copied and paste like a picture or something.I wish yahoo could go back to how it was in 2002 and so on it was fun and you always found people to chat with and carry on interesting conversations