When I enter yahoo chat room, why am I always being ask to verify my account?

To help prevent spam and bots from disrupting your Yahoo! chat experience, please click here to verify your account (this link will open a new web browser window). This step is required before you can begin chatting. http://captcha.chat.yahoo.com/go/captchat/?img=http://ab.login.yahoo.com/img/Tkj8k.VZFekHoO7pLc_hN8GSon9Hz1vBYKcdppVhyMQYuy.meV1Xa5ebTlIN.kpQyyaA_mwSDjgiuLtT4i0xXjmo.jpg&.intl=us )