Twitter has a serious flaw in its user interface, and I’m surprised it hasn’t been fixed yet given how popular the service is. The “block” link in the right hand column of user pages has undergone a number of changes in the past months:

Notice how the link appears immediately under the “message” link for sending direct messages. Now, users probably rarely block their followers, but might direct message their followers very often. A mouse slip of about 10-20 pixels might cause the user to accidentally click “block” instead of “message”.

This wouldn’t be that bad of a problem, but Twitter has dropped all confirmation steps from the blocking process. This means that if you accidentally click “block” on a follower, you will instantly break the follows between you and that user (both ways), and that user will be added to your block list. If it was an accident, there’s no way you can cause the user to re-follow you. That user must do so themselves.

Previously Twitter brought you to a whole new confirmation page to ensure that you indeed wanted to block that particular user. That then changed to a Javascript popup, which was still acceptable. However, this no-confirmation style is a huge mistake, and a simple search of the terms “message block” will return tweets of users who accidentally blocked their friends.

Cmon Twitter.