SingerDemi Lovato yesterday beseeched her fans to stop sending threatening tweets to comedian Kathy Griffin, who had referred to Lovato in unflattering terms during a recent Twitter Q&A. "Y'all gotta chill with sending hate towards other people," Lovato, 21, tweeted. "Regardless of what they say or do. . The cruel things some of you are saying can really, REALLY hurt people. It's called cyber-bullying and somethings should NEVER be wished upon [someone] EVER. . . . I really appreciate you guys always having my back but this is going way too far."