I'm looking for new people to follow and network with on Twitter but I'd like to conduct a more targeted search rather than just randomly follow people who follow a particular Twitter account. I'd like to input a list of 2 or more influencers' Twitter accounts and get a list of all Twitter accounts who are following every single influencer I specified on my input list. (For example, suppose I want a list of all the people who are following both Mark Cuban and Barak Obama.) Is there a tool out there that lets me do this? If not, would it be possible to program such a tool using the Twitter API?