How politically candid should profs be with students?

In her blog post Gotcha! How Open is too Open? professor Lee Elaine Skallerup frets over how candid she should be with her students after suspecting one of them used an iPhone to record her political comments during an informal meeting:

The take-away from the rise in technology in higher education? Don’t be yourself. Sorry, Academia, I can’t, I won’t, do it.