Twitter has updated its @ setting so that people who follow an account will no longer see that account’s @ replies.  However, people can still see account names mentioned with @ as long as it’s not a direct reply.  Here’s an example:

Replies @account won’t show:  If an account you’re following replies to @account, the message to @account won’t show in your feed.

Mentions of @account will show:  If an account you’re following posts an update that mentions @account, you’ll see that in your feed

Twitter’s system couldn’t handle the load so they were technically pushed to this solution.

Personally, I think this is a good solution.  It still offers serendipity, minimizes @ noise, and prevents calculated @ sniping.  Hopefully, this update won’t ignite (yet again) moans that “Twitter is Worthless“.  Twitter isn’t worthless… how can it be?  It makes me money