How do you combat projection when its used on you?

I usually don't say much, mostly acknowledge it to myself.
Sometimes we don't recognize it as such until after a time. It's rampant on here. When someone continually mentions a subject or trait they apply to someone else or what they aren't, it becomes quite clear it IS their issue.

ETA: Really, most things we say of others are projections. We are not inside that persons brain or heart, we can not know. So what we accuse/perceive comes from [i]inside[/i] [i]us[/i].