Bernie Sanders's supporters are known to be very vocal and aggressive on Twitter.<br />They've been accused of harassment and vicious personal attacks online.<br />Now, Sanders is stepping in, begging supporters to stop their online harassment.<br />On Thursday Sanders urged an end to online "bullying or ugly personal attacks." <br />Sanders isn't doing this out of the goodness of his heart.<br />He's making the plea to his supports because their behavior could cost him the nomination.
