Communists on the moon !

[geoschmo]

That's the point, they are very small, and they don't add up. Unless all the vectors are the same they don't. Equipment would be planned and balanced in such a way that the majority of their forces cancel out, and the random movements of a bunch of people going in different directions about the interior of the station will for the most part cancel each other out. The result will be a small net change in whichever direction has the largest amount of force being applied. But the net change will be well within the tolerance allowable by ordinary station keeping thrusters. Docking equipment has tolerances and extra reinforcment to allow for minicule variations, and if a particularly delicate manuver were neccesary, you could always broadcast a warning on the intercom, but I don't think it would be neccesary at all. The computers and thrusters ought to be able to easily handle it.

Geoschmo