This paper reflects on the metamorphosis of youth movements in the transition from the digital age to what we can call hiperdigital age (that is, the age of the social web). This transition is synthesized in a terminological change: Generation @ or At Generation versus Generation # or Hashtag Generation. The paper is organized into two parts. The first section takes the discussion in an article published fifteen years ago (Feixa, 2000) and the differences between one and another generation in the following comparison: history of the significant (ie, Signs @ and #) and meaning of the two terms. The second section, from the comparative analysis of the dilemmas of each generation, approach the transitions and theoretical features of the current generation # or hiperdigital generation. Social movements, often featuring youth, are where these theorized transitions are manifested in all its glory. Key words: youth, generations, information society (Social Sciences Unesco Tesaurus). Autors key words: generation @, generation At sign, generation #, generation Hashtag.