Offtopic1: I personally think the best What If? is the Glass Half Empty one, but YMMV.
Offtopic2: Google tells me there are approximately 3000 satellites in orbit (a lot of 'space trash', but not so much of that is going to be of sufficient size to survive re-entrywith still sufficient mass), and elsewhere I see that the total number of satellites launched is slightly above 6000. (Wiki lists 8300+, but that'll probably include all easily trackable fragments.)
Let's do an abbreviated What If? on those facts. Assume a full 6000 viable projectiles to land on the surface of the planet, which is 510,072,000,000,000 square metres. That's one projectile for 85,012,000,000 square metres, or a circle around 331 kilometres in diameter (ignoring issues of spherical geometry, of course, but would not be overly different if I hadn't). Restricting to land areas only, call that a 180 km diameter circle. Aiming at cities? There are... hmmm... it's an arbitrary designation at best, so let's take the 1054 (or so) cities with half a million population or more, and drop (almost) six whole satellites within their limits... Except that's probably far less impacts than car accidents than they'd normally suffer, on any given morning during the rush-hour.
You're going to have to hope to bop a particular person (or perhaps building) on the head with judgement from on high, strategically. It's going to be of limited use, unless you pick the target very carefully, or happen to have something (like a subcritical reactor) in the satellite that can cause substantial (useful) damage outside the initial crater.
Maybe not offtopic, while editing the above, my browser has crashed (and had to be recovered) twice. I've just navigated the XKCD tab back to the Fridge one (1109?), so that if it crashes again, I can rule out. I also lost Audacity (doing something in the background) or, because of Audacity I lost the browser. I shall re-open that to do what it was doing, to replicate conditions accordingly. This is an old machine, and might just benefit from a reboot or something.