Alright, we've all been having fun with the Unicode mirror character here on meta.
And now we all know how to do it.
Yes, I'm a culprit here as well, and I accept that.
But I just realized that it can be used to spoof usernames (at a glance, that comment looks like it came from our mod)
Please can it be stripped from comments? (keep it on MSO if you wish, the link styles are different so it doesn't work)
Note that it can also be used to spoof links in posts (see the "what can it be used for" section here)
This cannot be easily "waved away" as being caught on a per-case basis. SO has many posts which receive little or no attention, and a malicious user can easily play the Nigerian-prince trick on a newbie (Ask him for contact details/password/whatnot). Additionally, a clever username change can make it look legit even for more experienced users:
(No, I didn't actually change my username, I just Chrome inspector'd it ^.^)
So why not just strip it from comments? (and possibly posts)