While obviously no one's immune from the possibility, I'm sure the Alwil/avast team is extremely cautious about the possibility of their site being hacked and takes appropriate precautions. That's true of anyone who's in the business of providing protection software and services.
And I think you'll find that just about anyone in the a-v field in particular wants to know at least roughly (country or region, at the very least) where you are, so that if you report a virus to them they can keep track (jointly, they mostly cooperate well with each other) of the spread of such things and where they're most active. Look at the geographical stats readily available at "big-name" sites like Trend, for instance.
