Tasers dont paralyze you. They hurt like hell while they are on, but as soon as they turn off the juice you pretty much go back to normal. Before you are issued a taser as an officer, you are tased yourself so you know exactly what its like.
This is what Ive read as the background of this story (read this on Tribalwar, and some posters in the thread were witnesses to the event). The school library after hours will only allow students in. They know people do papers late at night, and thats apparently what this guy was doing. They announced that they were making the rounds to check student IDs. This guy refused to show his, and then later said it was back in his room. They asked him to leave again, and he refused. So they called campus police (which in this case have all the same authority as regular police).
This next part is a little fuzzy. Some say he was already following orders to leave when the officer put his hand on his shoulder to escort him out. Thats when the video starts...the guy freaking and yelling. Other reports are he wasnt following orders at all so they grabbed his arm to escort him out. Either way, once the officer grabbed his arm the dude goes limp and wont get up. They warn him about what they will do if he doesnt comply, he doesnt, so he got tased.
Pretty much the guy is a dumbass. They ask for ID, you notice you dont have yours, go back to your room to get it, come back and finish your paper. Instead you decide to be a defiant asshole for no reason and got tased + probably spent the night in jail.
A lot of people commenting on tasers dont really know a lot about them or how they are used. Luckily, in that same TW thread a few cops posted. The taser is relatively harmless and can save both sides from serious injury. Cops dont have to get in a fight if the guy resists them, break his arm trying to cuff him or whatever. This situation was exactly what the taser is meant for.