Yahoo allows anyone to see if anyone else is online. The only way to avoid this is to go to http://chat.yahoo.com and click on edit profiles and check the box that says “hide my online status” If you do not do this then it will be widely available to anyone by going to http://opi.yahoo.com/online?u=USERNAMEHERE
Put the username where it says “usernamehere” and it will show either an online or offline status indicator. It is legal. It is available. It breaks no laws. It has possitive uses such as knowing when someone who stalks you is on or offline. I do not advocate nor do I condone any illegal or innapropriate behavior. I simply feel it is a good program because it allows a person who is being stalked to at least check (in most cases) whether or not a person who is stalking them is online. In this case they can avoid or know to keep their guard up if they choose to chat. It is not wrong and that is only your opinion. All it does it is transfer http://opi.yahoo.com/online?u=USERNAMEHERE to your messenger. Not illegal. Not wrong. Good programs can be put to bad use, but it is not the program that is bad. People can use programs in a bad way-but that does not make it a bad or wrong program. Yahoo has not tried patching it because public view of online status is a persons choice.