Why are there overly sensitive people online?

[Maddie]

I noticed in forums the majority of them seem to suffer from some mental illness, namely a personality disorder..

I made a comment about Demi lovato, she posted a twitter picture of her "natural makeup" I commented on her pose, and that I would find her to be a decent person if she got the help she needed and stopped pretending to be someone she is not and lying to her naive young fans. Within 5 minutes I got 30 messages in my inbox, people or "stans" (stalker obsessed fans, see stan by enimen video for reference) jumped on me saying I'm a horrible person for making fun of her eating disorder and that me saying, "I dont really know why some girls pose like that, jutting collar bone out like that on purpose.. why do they do it?" meant that I am making fun of her eating disorder, what a terrible disgusting person I am, and they usually included their own irrelevant personal issue/experience with an eating disorder. My assumption is that they are overly sensitive.. assuming that I'm making fun of a serious issue when I was doing no such thing.

I've had over 100 comments by 5 different people with similar "Stan"/eating disorder/overly sensitive backgrounds. I've also seen these same people jump on anyone's throat if they say anything remotely opposing any celeb they obsess over.

Did I say something wrong.. or are these people just not well in the head..?

[joon]

They have nothing else to do but get rid of all their hate.

[Naguru]

It is just to pass the time. I think so. Otherwise they feel bored.

[Surya]

necromancer

[Astra]

people on line are often mental, they are unstable and insane! people get death threats for making one "innocent" comment.

[Saffren]

Devotees (or fans, if that is what you prefer to call it) look upon their object of affection as the highest imaginable manifestation of their own aspirations, because those idols possess many ideal qualities which they would want in themselves. As such, they identify strongly with and see part of themselves within their idols.

Hence, they do not (or at least they would make no attempt to) draw distinctions between criticisms directed at their idols and criticisms directed at themselves.
They perceive all such criticisms as a personal attack.

Did you say something wrong?
'Yes' and 'no'.

'Yes', because you pointed out the obvious.
To them, that is blasphemy of the highest order.

'No', because these people are a suffering lot.
Their failure to comprehend the context of those criticisms is of no ones making.
You cannot be held responsible for their inability to deal with the truth.