Sometimes, the factions build underground bases in secluded areas of the planet, where they can perform any activity that's best left unknown to the population at large (and their competition). However, this secluded location gives us an opportunity to strike, loot the place and disappear into the sunset before massive reinforcements can arrive. On the other hand, each existing Secret Base steadily undermines our position (-10 Infamy daily). A Secret Base is bound to be filled with loot, information (which we can use to blackmail people and otherwise increase our global standing), and is a prime place to look for the highest-ranking members of a faction. The final stages of building a base are signified with massed Supply Ship, Frigate and Cruiser activity that lasts for a couple of days. Enemy Hideouts can't be detected by radar, it requires anchoring for a few hours within less than 1600 NM from the target.