SAN FRANCISCO:- Twitter said it was stepping up its long-running battle against online trolls, trying to find offenders by looking at “behavioral signals.” The new approach looks at behavioral patterns of users in addition to the content of the tweets, allowing Twitter to find and mute online bullies and trolls. Even if the offending tweets are not a violation of Twitter policy, they may be hidden from users if they are deemed to “distort” the conversation, Twitter said. The announcement is the latest “safety” initiative by Twitter, which is seeking to filter out offensive speech while remaining an open platform.