I was just about to begin responding to Charlie when I took note of yekke2’s post. I cannot really think of anything to add. Yes, it’s great that you listened to shiurim (although it’s not as if shiurim are inaccessible through any other mean), and it’s obvious there are positive uses to certain technologies, but I fail to see as to why that should change anything. The negatives far outweigh the positives, and as such bringing them up is facetious, as Y2 has said. And besides, why not keep the positive content and block everything else?
It is sad that instead of changing their behavior to suit halacha (in this instance, a mefurash gezeira d’rabbonon,even apart from yichud), they try to subvert halacha to suit them. No Rav with any authority could advocate unfiltered, unnecessary, or unfettered internet use. Fact. I would be interested to hear the source of your ‘daat’.