I just tweeted a link to this question What is the best C++ interview question? and the content had the two + signs (for C++) replaced with spaces. I edited it back to + signs, but I don't see why it should do that?
The plus sign (+) just needs to be encoded before it's sent to Twitter.
So the part that's this:
should ideally, if we're wanting to double-plus the face (which itself isn't on the question's URL), be this:
Twitter just interprets the plus signs as a space because that's the shorthand.