I'll do this sometimes in web forums. There are certain points of view expressed certain ways where I already have a pretty good idea of exactly what the poster

I'll do this sometimes in web forums. There are certain points of view expressed certain ways where I already have a pretty good idea of exactly what the poster's opinions are, how they'll defend them, and how they'll respond to any questions, and I know my likelihood of getting them to reconsider or maybe even engage on terms I consider reasonable is nearly zero, but I might reply anyway just so lookers-on can get a sense that there are alternatives to that POV (and that, after a couple back-and-forths, that maybe their position isn't as strong as their very-certain tone implies)