Whewould you hide?

I know my comment is late in coming, but I figure I'd throw my two cents in on this.

The jovian system is a good place to muck about, lots of moons and dust rings to hid out in. Gives you three other planets to use as well. Saturn, Uranus and Neptune, them being apart of the Jovian system. The asteroid belt is another good place to hid your illegal activities. As the other have made good points on this. The outer solar system is the best place to conduct this due to as you get closer to sol, you run into such issues as radiation. Our sun is a killer if you don't have a planet with a good magnetosphere around it.

I suppose this really all depends on how far in the future you plan to make this, 50, 100, a 1000s? Do things far enough forward it is not a hard idea to buy if they have force-fields to protect their ships, and engines that are all electric with phenomenal thrust, thus meaning with some kind of nuclear power supply one has years of fuel to burn making the worry over the delta v less important.

Other good hid outs would be protoplanets on the far fringes of the solar system. Ceres, Pallas, and Juno...