Canoe Camping - Moose, Fishing, Catch & Cook Trout: 3 Days in Algonquin Park

Mid July 3 day canoe camping trip in Algonquin Park
We had a beautiful first day paddling to the lake where we would spend night 1, only to find a big group of people stationed at 'our campsite'. On a lake with only one bookable site, a place we had stayed before, we knew this was not a good sign. We tried to get their attention as we paddled along the shore. They awkwardly ignored us.. It was almost 2pm and their camp was completely set up while they cooked food over a fire and blasted music on a radio - looking like they were having a wickedly good time. Knowing that they were camping without a permit (or off permit) We called out and spoke with one of the members of the group - they had just arrived! We told them that we had the permit booked for the lake, and they let us know  there was another site. We knew there was, but it wasn't a nice site, it was an extra site for emergencies, this was the site we planned to stay on when we booked, and there shouldn't have been anyone else on the lake unless there was an emergency and they needed to take the extra site. They said they were from a camp and were 're-routed', but after some discussion they did end up saying that they understood and that they would move onto the other site. we paddled around and waited for them to move along to the second site, and then proceeded to set up our camp on the site we had planned to stay on. Luckily in this scenario it was obvious that they were camping off permit with only one bookable site on the lake, but on a big lake, I can see how it could be impossible to identify who has stolen a site. This type of behaviour can put people in dangerous situations, not to mention suck the fun out of a trip, endlessly paddling around a huge lake with all sites taken.
After this unpleasant experience, we enjoyed the rest of the day and evening.
We left early the next morning before eating breakfast to move on to the next lake we had booked. James fished as we paddled along. we arrived at the next lake, one of two sites still had occupants, which we had expected due to the time of day. We unloaded at the free site and cooked up some breakfast. We thought we might check out the other site after the occupants left, but the one we stopped at was perfect and decided to stay.
We set up cap, swam, enjoyed wonderful weather and were surprised by the sighting of a moose and her calf. Later that day James caught a trout and he cooked it up over the fire. A perfect dinner.
The next day we paddled back out while James caught more fish, and we lost Emma overboard with excitement to one of the catches. After fishing her out of the lake we ended the trip content and relaxed.