In This is Not My Life groups from outside Waimoana came into the community and kidnapped (or saved, depending on your point of view) people. There was also a group working on extracting Alec later in the season.
Are these the same group? I wasn't really clear on whether there was one "resistance" group that was trying to rescue people and were also helping Alec for some reason, or whether there were multiple groups with conflicting (overlapping?) goals.
If this wasn't answered in Season 1 and left for Season 2 to explain, then that's a valid answer. My impression was that it was meant to be clear, though.