[quote=@Silvan Haven]
<Snipped quote by Ryonara>

I'm not an expert on this by any means but uh...pretty sure you start getting the teacher's involved at that point and risks of getting expelled if the target of the blackmail does the logical thing and tells on you.

And telepathy well, unless the other person is a telepath the only way to hear their thoughts is to get inside their head. Having an entirely different person poking around in somebody's head is bound to catch their attention.
[/quote]

Ebon may or may not actually black mail Shiro. At this point he is looking for Sapphire's daggers with the intent on using them for his own gain, which may involve black mailing Shiro. Or just calling finders-keepers. 

And to me telepathy is much like hearing someone talk: All you have to do is listen. You can whisper to try to hide it, but that implies you know someone is trying to listen. Most people aren't aware of telepaths since they don't go around making it obvious someone is listening in on their thoughts. And as long as Ebon doesn't actually try to speak back, most people wouldn't notice he's listening in unless they actually notice him.

It may be obvious since he has to look at them, but would you really think that everyone that looks at you is reading your mind? Ebon glares at people all the time anyways.