The steadily growing popularity of the Internet leads to many new social phenomena including verbal aggression on the Internet called cyberbulling or flaming. This study aims to describe verbal aggression in the comments on the polish Internet. Such comments on various subjects and from websites with different levels of anonymity were analysed. The data showed among others, that the percentage of aggressive comments is proportional to the level of anonymity provided on specific websites and thatusers prefer to express aggression by using offensive, but not vulgar, language.