Even if you think it’s “not fair” that someone in power can (and will) judge you based on your behavior in a social space, it’s a fact. Be liberal and tolerant when it comes to interpreting and responding to the behavior of others online, but be conservative and restrained about what you do.
I write nothing that I wouldn’t say aloud to anyone. I am also very aware that my students follow me on Twitter, as I use Twitter as a pedagogical tool. I don’t say or tweet or write anything that I wouldn’t say to them. Conversely, these students often follow who I follow on Twitter, and I don’t want them to see other professors publicly laughing at student effort or intelligences. I don’t make malicious comments about students or colleagues, but since I follow or am followed by those that do, I wondered if their attempts at humor affected the way others saw me.