question thats been on my mind

Nobody is 'entitled' to anything. However, blue buff is generally considered to belong to the mid after the first one goes to the jungler.

The thing with blue buff is that it's practically a requirement in mid, especially if your lane opponent has theirs. Some mids need it to help them farm efficiently. It also lets them spam a few more spells for harassment in lane. And any mid with a big cooldown ult (karthus, for one) should have blue if possible the first time they use their ult. It'll make their ult come back up sooner with the CDR.

No, but it should be expected that the jungler will give mid the blue after a certain point.

Not at all. The jungler is entitled to "THE JUNGLE!" It is a common curtsey to give the mid blue unless the mid doesn't use mana because generally blue is more useful to mid lane. Some people just rage because they don't realize they don't always get what they want.

Personally, I always wait for a ping. I'm never going to assume someone wants to do something nice for me and potentially read it wrong and steal it. But ping me over once, and I'm going to assume it's for me into perpetuity unless you start pinging me away.

Whether or not the pings continue, I always say 'thanks.' =)

You are not entitled to give the blue buff to anyone. but as a courtesy you may offer the blue buff to one you see fit to use it to there best of there ability.Remember teamwork your only as strong as your weakest link so just work as a unit and have a strong enjoyable time :)

When I jungle and I'm ready to give up blue I usually ping it and ask them to come. And when I'm on a mid that really needs blue as soon as possible (like Anivia) I try to ask for it as soon as possible.

But is it really a surprise that certain summoners feel entitled to everything in the game? There will always be those people that rage over kill steals, minions, whatever. If they rage, I tell them that I would have given it to them if they had asked. That usually works to stop their rage.