Regardless of whatever the final destination of these stolen resources may be, we want to put a stop to it! The alien structures appear to be susceptible to energy weapons. We should research their vulnerabilities further which should allow us to construct automated base defenses to take them out. Longer term we should look towards researching improved methods of resource distribution which are less vulnerable to attack. As a stop-gap we can kill them using our ray gun (V), but they'll certainly be back quickly.