Carol Howard Merritt raises some pertinent points in her essay. As a Christian leader or a scholar you have two options, either stay out of the internet completely (i'm not talking socially, i'm talking professionally) or make sure there is enough content out there that what is yours will overwhelm what is written about you by others.
Admittedly, I'm not sure anyone cares enough about anything I have written to defame me yet. However, there is a danger that even what you publish online can be misunderstood, for example, I wouldn't want to be judged professionally on the content of this blog, not that I don't stand by what I write, but this is a hobby and it is uneven. It does not accurately represent my own passions and emphases, or even the quality of work i do when i am paid for it! If I were to take on a preaching ministry in a church, for example, it would not resemble my blog very much at all.
But there is also a way in which as a Christian leader or scholar you have a responsibility to be blogging or running a website of some sort in the hope that you can counteract all the crazy stuff out there. We musn't leave the internet to the maniacs with their well worn copies of Vines and Strongs and the crazed glint in their eye. And the fact that we don't write in capitals, and do not have fluorescent backgrounds to our webpages should only be the start of our credibility.