Yep, you can do blank posts. Not quite sure where the fun in it is and I would imagine that once the team are back in the office on Monday they'll fix it so that one can't (until someone finds a new way and they fix that and so on ad infinitum).
There doesn't seem to be anything sinister about the links anyone has posted, indeed, none of them have actually gone anywhere.
Search isn't working for these posters because when it finds the blank threads it has a bit of a wobble and gives up.
As you were.