Yes, there are certainly aspects of computers, the internet and especially social networking and instant-texting that have a net negative impact on our lives.
But this argument strikes me as a "I'm such a victim" argument. Surely if you allow some device to have such a massive negative impact on your life then this would be the case even pre-90s before computers and the internet became mainstream?
- Maybe you might have spent too much time hanging out at your local bar? - Perhaps you'd have been addicted to television?
The one area, where I wholeheartedly agree and recognize the serious dangerous of the internet and computer devices is in children. The threat of cyber-bullying and indeed, rather more subtle, the attention-seeking culture of always producing content at a young age is IMO, very scary when thought of in the context that these will be future adults who didn't know better. We need to guard against these enabled social pressures like we protect kids from smoking, drugs, alcohol and even to a lesser extend (i.e. it's not illegal) addictions to things like TV, video games and other behaviors that they might fall prey to.
I guess, summed up what I am saying is: It appears that there the internet has developed a predatory nature on one's attention that extends to threaten one's social status and reputation.
Where I disagree is that - as adults - we know better and can combat this with self-discipline and by choosing our friends/social circles wisely (I don't engage with friends who constantly text or post online. I'm happy to meet but they know not to expect my participation there).
Where I agree is that, children are vulnerable to this and must be protected AND TAUGHT how to treat / interact with the internet.
Unfortunately, since this is relatively a new thing in society. We have not yet developed a solid culture around what is acceptable and what is not. Just like it is inconceivable now to smoke inside a closed room, or someone's house, I do hope that in the future it would be inconceivable to upload compromising information/pictures to random servers in foreign countries. But alas, we are not there yet.