Upcoming missions to Mars' moon Phobos

Space.com has an article today on past failed missions and three upcoming missions to Mars' larger moon Phobos, by Russia, Canada, and NASA. Since Phobos orbits Mars that means that it has the same infrequent launch windows and a two-way mission takes three years, but naturally the miniscule gravity there makes it very easy to take off after a sampling mission for the mission back. The most interesting part of the article is this one:

The Russians are not the only ones who dream of Phobos. Another mission headed by Optech Inc. and the Mars Institute, and funded as a concept study by the Canadian Space Agency, is called PRIME, for "Phobos Reconnaissance and International Mars Exploration." The PRIME mission would be composed of an orbiter and lander, and each would carry 4 instruments designed to study various aspects of Phobos's geology. Yet another mission concept, the Phobos-Deimos Sample Return Mission (SRM), is being studied by NASA's Glenn Research Center. This mission would rely on low-cost electric propulsion to land on Phobos and Deimos and bring back samples from the two moons.

These mission studies are proceeding in part on the philosophy that Phobos could be key to the future human exploration of Mars. Not only does the ease of landing and taking off from Phobos make it a good pit stop between Earth and Mars, but because Phobos is tidally-locked, always showing the same face to Mars, it could be a stable location for a Mars communications relay or some sort of monitoring station.

...especially the second paragraph. I've never seen a paper dealing with this issue but later on I suspect it will become quite large: given the tiny gravity of Phobos and Deimos, anyone on the surface facing Mars would be able to lob rocks at the planet's surface since the escape velocity is only 40 kph. A pitcher in baseball, however, can pitch balls at speeds three times that, and that's without even using any tools whatsoever. Naturally, during the first few years of Mars colonization this would not be an issue, but what happens when the population there blooms to a few thousand? Who would be able to get permission to work on waystations on Phobos and Deimos, and could we trust that everyone up there would never succumb to a sudden urge like that?

This is why I imagine that later on these two moons are going to become multinational and very well-monitored, because there's no way that one nation is going to be happy with the presence of a single nation above their heads. Weapons technology can be restricted on Earth due to the difficulty of developing advanced weaponry, but to cause massive destruction on Mars from Phobos or Deimos all you would need to do is lob rock after rock at the surface. The exact size needed to break through the atmosphere I'm not quite sure about, but asteroids need to be a few dozen metres in diameter to reach the surface of the Earth, and Mars has an atmosphere somewhat more than a hundred times thinner than ours.

Luckily (or unfortunately, depending on how you look at it) we're nowhere near having to deal with this issue. There are naturally some very good benefits that come from Phobos' location as well, such as the ability to refuel craft in Mars' orbit - craft could be sent up with the minimum of fuel to achieve orbit (thus saving a lot of money and also allowing for more space to be used elsewhere), and after this happens refueling could take place with some sort of object easily launched from Phobos or Deimos, which would link up with the craft, refuel it and it could then be on its way back to Earth.