It's impossible to "destroy" the English language. Language evolves over time, and the Internet is simply causing it to evolve in unexpected ways. I don't always like what I see happening to it, but I'm old school and I know it, and I also realize it's just me being resistant to change. It seems to me that if we let ourselves, the older we get the more we'll hate the world, unless we allow change and go with the flow.
Of course some of what's going on is just language fads. There were people who thought the hippies destroyed the language, but some of the language they used, if one uses it today, just sounds hokey and dated. It's out of style, and the older forms still exist.