A while back, Twitter made an announcement that comes into effect today. The new rules the company set for developers forces them to switch to SSL encryption.
Connections to all its API URLs for apps that have not enabled the encryption standard will be blocked, which may leave numerous broken apps.
The new requirements were made public a while back and Twitter even issued a reminder yesterday, to make sure that everyone was on the same page about the changes.
“On January 14th, 2014, connections to api.twitter.com will be restricted to TLS/SSL connections only. If your application still uses HTTP plaintext connections you will need to update it to use HTTPS connections, otherwise your app will stop functioning. You don't need to wait until deadline to implement this change, given that api.twitter.com already supports the recommended environment,” Twitter wrote.
The change is supposed to increase security and user privacy. Several other companies have taken the same steps as well, including Google and Facebook.