Filtered? Usually. Fake? No.
I do keep an unfiltered journal with more complete details of my more tentative and exploratory thoughts and reactions and details which affect other people's privacy and sensitivities and would therefore be completely self-serving and inappropriate to broadcast here.
I don't consciously "try" to project a particular image of myself here. Why would I? I don't know most of you people, and the ones I do know can come talk to me about this stuff rather than relying solely on my blog, and for those of you who know me personally, I don't think I could somehow fool you through my blog posts.
What some people regard as frustratingly "filtered" is often actually what I regard as my truest expression. I tend not to go off on the hyper-emotional rants most bloggers seem crazy for or seem to think is most "authentic". My passing emotional reactions are valid, to me, and are occasionally useful for others besides my trusted friends and family to read or hear, but are not the "truest" expression of how I think and feel about things: the truest are the lasting impressions and thoughts, after the reactions born of sensitivities, insecurities, defenses, etc have passed.
I think most people aren't used to...eh, nevermind. Maybe I'm just different from a lot of bloggers and blog-readers...and maybe most people...in some pretty fundamental ways. *shrug*