Basics (1) - S2-E26
Plot hole: The Voyager was continuously attacked by small Kazon attack ships. Yet the Captain never orders to increase the warp speed to evade them (In previous episodes we saw that the Voyager has much higher max speed than any ship in the Kazon arsenal). They simply travel at a lousy Warp 2 and wait to be attacked. It would make sense to travel slowly if they were trying to avoid being detected by Kazon but that was not the case. They were attacked constantly. Voyager may be more maneuverable at slower speeds but if you can outrun your pursuers there is no need to maneuver to avoid them. Also, if Voyager was traveling at a higher Warp Speed, there would be no way for the Kazon to array fighter craft ahead of Voyager as they would not be able to overtake Voyager. If they could, there would be no reason to deploy the fighter ships, they could simply engage with their capital ships.
Chosen answer: Before Q sent the Enterprise to the beta quadrant to officially contact the Borg, there were already indications that the Borg was beginning to reach Federation territory. There were remarks towards the end of the first season of the Next Generation that several of the furthest Federation outposts were being attacked by some unknown enemy. They suspected the Romulans, but when contact with the Romulans was re-established, they learned that it was not them. The Hansens had simply figured things out much earlier than anyone else in the Federation. They learned about the Borg nine years earlier, but Starfleet mainly took notice when their outposts started getting wiped out. It is logical to assume that there were indications of Borg scouting parties and research efforts well before that.
Garlonuss ★