1) Because the email address you supplied when you registered no longer works. As a result, you cannot be sent notifications.
Please DO NOT use disposable addresses here - they will expire and you will forget. You can hide your address if you wish. Just check your profile for the options.
2) Because you posted a spam-like invitation for people to visit your "affiliate website" so that you can earn points or dollars or win a trip to Las Vegas.
3) Because you posted ads for pirated software or discounted cellphones or cheap cigarettes.