. The only exception was Species 0000, who couldn't be scanned or assimilated and could break out a Death Star-type planetkiller attack in an instant. Now, the Borg couldn't deal with that at all, but Imperial technology is quite a bit behind something like the Federation, or even the Pakleds for that matter. Also, it takes a bit of time for the Death Star's weapon to target, charge up, and fire, which is long enough for the Borg to scan, adjust, and devise a strategy to combat it (EDIT: Like what Sith just said). 