For the nearly 20 percent of Americans who experience severe online harassment, there’s a new company launching in the latest batch of Y Combinator called Tall Poppy that’s giving them the tools to fight back. Co-founded by Leigh Honeywell and Logan Dean, Tall Poppy grew out of the work that Honeywell, a security specialist, had been doing to hunt down trolls in online communities since at least 2008. That was the year that Honeywell first went after a particularly noxious specimen who spent his time sending death threats to women in various Linux communities.