For young people, in addition to positive experiences, there are risks and negative consequences in the usage of the Internet and Information and Communication Technologies (ICT), such as forms of online harassment. At present, there is an open debate regarding the definition and issues concerning the nature of cyberspace, given the different ways that the scientific community and the general public express this phenomenon (for example, cyber-bullying, cyber-aggression, cyber-harassment). The present research surveyed 585 Italian students via an online questionnaire regarding unwanted online attentions (UOA), an umbrella category of online behaviours directed at harassing, offending or attacking someone. Two exploratory factor analyses examined the experiences of self-identified victims and perpetrators in order to better describe and identify UOA. The findings identify six dimensions, namely, for the victims: harassment, impersonation, denigration and ordering goods, physical threats, hacking, and disseminating private information and audio-video material without permission; and, for the perpetrators: disseminating private information and material without permission, physical and social threats, hacking and stealing identity, harassment, denigration and ordering goods, unwanted emails and spying, and impersonation – thus illuminating more specific categories of UOA. These findings will make it easier to recognize these expanding and potentially very dangerous behaviours, leading to the development of better prevention and intervention strategies.