Copy this space: . Great. Now never again will you be forced to place an awkward "." in front of the @ on Twitter just so all your followers can see you scold @realdonaldtrump.
Last week, Isaac Hepworth, who as his bio explains has the coolest job at Twitter ("I do Unusual Projects at Twitter"), posted on his blog this hack for inserting a zero-width space into a tweet to essentially break Twitter's rule that only mutual followers see tweets that start as an @ reply. The space still counts as a character to Twitter, but it doesn't look like one to your followers.
As handy as this seems, the problems with this technique are multiple.
For one, nobody understands what you're doing at first. People will think you screwed up and forgot the period, or that Twitter is broken somehow. You will have to explain yourself.
Or you can just continue to mess with them.
Secondly, there's no way to directly type this special character on a Mac. Mac users like myself have to copy it from somewhere else, or pull it up from a special character selection menu. (If this all seems rather strange and hacky, that's because it is.)
There is also a script that you can run if 1.) You have a PC and 2.) You are tech-savvy enough and care deeply enough to implement a script for tweets.
Otherwise, again, just copy this: , save it somewhere, and enjoy: You're now breaking a Twitter rule.