Brake fluid question

[Fid]

I was doing some re-arranging in my garage today and I found that two weeks ago, I inadvertantly topped off my master cylinder with DOT 3 fluid when the car contained DOT 5 (silicone fluid). I've heard you are not supposed to do this but so far, the brakes work fine.  Anyone have firsthand experience with why this shouldn't be done? I'd like to hear about it if you do.
Thx.

[stroker70]

If you don't want to flush the entire system, you could remove whats in the master cylinder and refill with dot 5. If there is room a cheap turkey baster works fine to suck out the fluid. I would not leave it the way it is.

[Fid]

That's a good point. Since liquids do not compress (the whole principal behind what makes hydraulics work) what I put in should still be right there at the top.  I put it in with turkey baster!  I will remove it with one and refill.
I am still curious as to what problems this might cause - brake failure? Sticky cylinders? Any comments on that.