Are there additional limits if you are following 2000+ accounts?
The rules about aggressive following and follow churn still apply. In addition, every user can follow 2000 people total. Once you’ve followed 2000 users, there are limits to the number of additional users you can follow: this limit is different for every user and is based on your ratio of followers to following.
When you hit this limit, we’ll tell you by showing an error message in your browser. You’ll need to wait until you have more followers in order to follow more users—for example, you can't follow 10,000 people if only 100 people follow you. When you reach a daily or total limit and we show you an error message, you've hit a technical limit imposed to limit egregious behavior by spam accounts and to prevent strain on the site. These are just the technical limits for your account; in addition, you are prohibited from aggressive following behaviors. These behaviors may result in account suspension, regardless of your account's technical ratio.
Limits improve site performance by ensuring that when we send a person's message to all of their followers, the sending of that message is meaningful. Follow limits cannot be lifted by Twitter, and everyone is subject to them, including verified and developer accounts. Based on current behavior in the Twitter community, we've concluded that this is both fair and reasonable.