I have a feeling that you are repeatedly walked all over in your personal life. Perhaps it doesn't quite register with you what is going on, perhaps you just feel constantly disrespected by people for reasons you aren't able to comprehend and no one else seems to ever say anything about this societal abuse, so you chalk it up to some defective victim mentality you think you fall into.
So you don't really feel any anger toward other people, mainly because you don't quite understand your interactions with these people who treat you like a lower-class citizen (and they treat you this way because you LET them, not necessarily because you have done something to outright deserve their disrespect), but you know that something is wrong. But your lack of perception combined with your naturally timid nature creates this rage that you don't even quite know exists until something that can't hit back frustrates you.
And computers can do this to people. They're so fucking smarmy and their attitude is so goddamned indifferent and they are so good at showing just how little they care about the major inconveniences they cause in people's lives when they decide to take a complete shit at the most inopportune times. Where the fuck do they get off freezing up on you out of nowhere?
And they think that just because they cost a lot of money and they can't fight back that they're just completely immune to any sort of attack, whether it's personal or physical. So they fucking abuse this and push the limits of decency and good taste because they (falsely) assume you won't do anything to them.
They're like the dumbfuck at the zoo who taunts the lion in his cage every day until one day the lion gets out, and that lion is YOU, and you tear the thing to fucking pieces just to show them a goddamned lesson, just to show them what happens when you fuck with the lion in his den, just to remind them who the REAL King of the Jungle is.
And all this time you don't realize that this rage building up is caused by your inability to man up and challenge those around you who treat you like a castrated lemming and so you take it out on a convenient yet deserving target.