Could there be a minimum black hole within each moon, every planet, every star?

One of my favorite fun facts about physics is that small black holes could indeed exist inside of the sun — or even any planet or moon. In fact, none other than Stephen Hawking himself actually suggested that this was a possible resolution of the "solar neutrino problem" (which has since been resolved with another explanation), "pulsarquakes" (now called "glitches"), and even Weber's claims of gravitational-wave detections (which have been discredited). You can read the paper in which he suggested this for yourself here. Although these claims are not currently accepted, the point is that Hawking (correctly, as far as we currently know) suggested that the sun could contain a black hole of as much as $10^{17}\mathrm{g}$, which would only have a radius of about $10^{-11}\mathrm{cm}$. This is so small that even inside the sun, particles couldn't fall into it at a very high rate, which means that the sun could actually survive for about as long as it has survived with little significant effect. On the other hand, there may be far smaller black holes, with even less effect, so it's quite possible that the earth itself contains one or more black holes.