So why can't you come on here at the library or at school anymore, Titan? Don't go blatantly disobeying them by deleting the parental controls (I'm sure you could if you tried), but checking in on here every once in a while from school or a library can't hurt.
And if you're going to debate this with your parents in a real, valid, thoughtful discussion, I must say this: learn about logical fallacies. Don't point them out to your parents blatantly like "oMg! That= IDIOT REASONING!!", and perhaps not at all, but just understand where they are using those fallacies, and eventually, you will be able to use that to your advantage, either directly or indirectly.
The only way you can win a discussion as such is to get your parents to take you seriously. You've already betrayed their trust a little bit by downloading all this FS garbage, and given your age, this will be extremely difficult. From past experiences, these types of parents are the most difficult to reason with. Above all: Don't lose your temper. Don't whine. Don't beg. Don't pester. Do think. Do be intelligent. Do be patient. Do be persistent.
If you don't win the discussion within a few minutes after its start, give it up gracefully and come back later with either different or improved points. Continue this process for a while and you will both have increased your parent's trust in you, you will seem more intelligent to them, more respectable, and above all more reasonable. If you don't get what you want through these said intelligent methods, at the very least in other areas of conflict with your parents you'll have a tiny leg up.
Also, try to pander to their conservative side at first. Trying to liberalize them blatantly early on will only piss them off. It will be difficult, but once you have their trust you can gradually start either pointing out errors in their beliefs in parental involvement, or gradually make them more liberal.
And here's the tricky thing: You could have the most perfect argument ever, your parents could agree with you, but out of spite, they don't let you do it. That's why you need to get on your parents good side about things. Do your chores and then some before talking to them.
All in all, you'll be one of the luckiest kids ever if you manage to persuade parents like yours to share your viewpoints.
EDIT:
BTW, the more your parents shout at you and beat you, the more you've outdone their ability to parent.