Referencing this post:
" To that end, and similar to some other companies, we will require you to work with us directly if you believe your application will need more than one million individual user tokens."
“Additionally, if you are building a Twitter client application that is accessing the home timeline, account settings or direct messages API endpoints (typically used by traditional client applications) or are using our User Streams product, you will need our permission if your application will require more than 100,000 individual user tokens.”
“Once you reach 200% of your current user token count, you’ll be able to maintain your application to serve your users, but you will not be able to add additional users without our permission.”
So the question begs, who do we contact at Twitter?