JPMorgan Chase & Co canceled a question and answer session on Twitter with a veteran investment banker after being flooded with insults, highlighting the risks companies take as they experiment with social media marketing. “Bad idea! Back to the drawing board,” spokesman Brian Marchiony said by email on Wednesday evening after the event with bank executive Jimmy Lee was called off. JPMorgan last week asked users of the popular microblogging site to send questions marked with the hashtag #AskJPM in advance of the session set for Thursday at 1 p.m. in New York. Some users simply made fun of the bank’s attempt to use social media, but many others chose to insult executives or ask barbed questions about bank’s recent legal problems and corporate responsibility.