Is it one of the single bolt designs? Like:

In which case yes. I've done it a couple of times, and had others on rides with me do the same. I personally think it's a design flaw; any pressure/impact that isn't directly above the bolt will be levering the bolt into tension and while they can go years without failing, eventually they will, and the bigger / heavier the leverage, the sooner that'll be.
I try not to use single bolt designs now, but one bike still has one on and I carry a spare bolt just in case. And seeing as you can buy spares for pennies if you know where to go, I change the bolt every couple of months or so anyway just in case. I still shudder at the feel of the shaft of the seatpost on my inner thigh as my saddle suddenly folded backwards at D2D.