In my one of my first blog posts, I wrote about what a LinkedIn IDK is and why you should know.  You have the ability to block people on Twitter and Facebook, and LinkedIn gives you a similar ability to block someone by disconnecting with someone, although in the case of LinkedIn you have to connect with them before you can block them (yes, I know, it sounds strange).  But the policy on penalizing someone without either the sender or recipient knowing it, which is the case of replying to a LinkedIn Invitation with an “I Don’t Know” or IDK, …