Red Flatworms or what?

[Dreichler]

So I posted this video on a Facebook reefing page for a quick response and convenience.  But all I really got was a bunch of “time to get out of the hobby” or “very bad get them ALL out”  and other comments close to that...  I’m wondering how big of a threat are these?  I just picked these 3-4 in the video out today from the tissue of my elegance coral.  The only damage to any corals that I can see is my grafted month cap seems to be turning white a little but I think that’s bleaching, so I moved it down some.  I have a potters angel and a leopard wrasse.  The leopard wrasse I actually bought to take care of a flatworm problem a few years ago.  So hopefully he can clean them up!  But what’s your guys opinions?