Since the time service began working 2 years ago, we've got around a million users - some of them decided to create an account and operate being logged in, others were using the system without login, which is OK. However, we discovered an increasing amount of attempts to hack our servers, which caused service interruptions for the honest and loyal customers.
We considered this situation to be inappropriate and unfair for our users, thus we introduced the authentication process for people who show interest in our service.
All registered users are forwarded to a standalone server, more stable and providing much faster response time. Also, that prevents registered customers from any kind of service interruptions caused by the service misuse by some malevolent users.
We know, in some cases, it may be annoying, but this is done for your own safety and we are constantly working to make the sign-in process as easy as possible. Should you have any suggestions on how to make it more user-friendly, please let us know.