Whenever new technology comes along people always get worried about it, as far as language is concerned. It’s not just with the Internet. When telephones arrived in the 19th century, people panicked because they thought it was going to destroy language. Then broadcasting comes along in the 1920s and people panicked because they think everybody’s going to be brainwashed.
Same with the Internet. People panicked because they thought the Internet was going to do devastating things to language.
In each particular case, what you see is an expansion of the expressive richness of language. In other words, new ways of talking and communicating come along. The Internet has given us 10 or 15 new styles of communication. Long messages like blogging, and then short messages like texting and tweeting. I see it all as part of an expanding array of linguistic possibilities.