He too says it 's impossible to nail down its significance at this point but listed a set of possibilities , from a sense of isolation to distaste for Facebook as an emblem of `` the status quo '' to something perhaps even more sinister . Brandon Griggs , the Tucson shooting suspect , has no social media presence . Psychologists say it could suggest isolation , resentment toward society . Only 3 % of 18- to 29-year-olds are on social networking sites , Facebook says . Others with the same name are being harassed on Pew .
Brandon Griggs , the Tucson shooting suspect , has no social media presence . Psychologists say it could suggest isolation , resentment toward society . Only 3 % of 18- to 29-year-olds are on social networking sites , Facebook says . Others with the same name are being harassed on Pew .