People are free to mimic any number of sounds that they choose

The internet is a tool. It amuses me that people think it will bring dysfunction to the english language, little realizing that any dysfunction that it appears to show or exacerbate is something that was already there, or symptomatic of trends and discourses that simply used to be less visible.

People who need to use the internet formally will do so, and continue along this line.
People who engage in more casual discourse will - as a rule - be much less controlled and formal about their speech.

It is not the job of the internet to teach prescriptive grammar - although it can potentially teach or inform on any number of things. Parents, educators, and people in general will have to teach, or perhaps inform, what kind of language is and is not considered acceptable.

I don't use webspeak, but I see no problem with people lol-ing and rofl-ing.
The internet is a medium of communication, and we cannot, and should not attempt to control how people communicate. I'm just happy that people can, and are, and will continue to do so.