Any breach of security on a system like this is a big flashing red-alert to me.
If it could lead an attacker to get ANY of their data... Persons, places, events, etc is pretty damning stuff to be exfiltrated.
Stalking/Domestic Violence, blackmail, timed robberies, you name it... That data shouldn't really be in anyone's hands in my opinion, but in anyone's hands (good guys / bad guys) it's pretty powerful.
It's a red-alert to you and me, but Flock won't care. People already don't want these cameras in their cities, but police departments buy them anyway. What does it matter if there's one more reason you don't want them?
That's why you or I would care, but that doesn't answer the question of why they would.
Large companies tend to be amoral. Unless it affects them monetarily (possibly indirectly) they're not going to care. Given what they do to make money, I don't see any of these things hurting them.
Apparently police are accessing the network via their personal devices. I highly doubt their security practices online are any better than this. I wouldn't be surprised either to see things that chinese manufacturers do such as intentional back doors.
Overall this goes from disappointing to fairly repugnant.
Many moons ago, I was involved in the technical side of volunteer work for domestic violence victims escaping abusive relationships with e.g. law enforcement (cops), who even fifteen years ago had sweeping powers to track and stalk their victims. Things like actual anonymous burner phones and the ability to e.g. create new email accounts without government identification were critical to the process of getting these people out safely, or alive, without fear of retaliation.
I can't even imagine how difficult this job must be nowadays, with bullshit like Flock spanning hundreds of police departments participating in their nationally-linked database. I have zero sources for what I'm about to say, but my instinct is that the political machines (expanding powers hidden behind "think of the children") behind how technology is evolving today has gotten people killed.
Getting persistent access to Flock's internal network is a high-priority item for every US adversary, who doesn't want free intel collection on the movements of persons of interest? Knowing who the FBI and local cops are monitoring in is the counter-counter-intelligence cherry on top of a self-inflicted dragnet surveillance cake.
Any entity with access to flock servers can virtually stake-out anyone/everyone driving past Flock camera to monitor their movements. In a hot war, this would provide actionable data to support assassination via road-side bomb/drone strikes.