I think it comes with all the usual caveats of "don't run super sensitive things on external networks". My guess is the motivation is for presentations and other "one-time" usages like that.
There is a flag to allow/prevent write access, so third parties wouldn't be able to use your terminal unless you allow it (I believe its disabled by default) . I also think (if I'm reading correctly) that it only shares a single process and will terminate the session when that process exits, which gives you a little added security in that someone with write access only has the same level of access as that process (which for some processes could mean a lot).
It would still be wise to put some sort of auth or other security in front of it if you're not trying to share with the whole world. I think I would be cool if there was some basic mechanism built in.
