Warning! Spoilers ahead for Venom #200
In Marvel's landmark 200th issue of King in Black invasion has truly changed the Marvel Universe going forward. There's now a lot more symbiotes on Earth than Flash realized, and humanity doesn't seem to be taking it well at all.
During King in Black, Knull the Symbiote God commanded his forces to invade Earth, covering the world with his symbiote legions. While several heroes were forcibly bonded to symbiotes and became assimilated into Knull's army, it appears as though just as many civilians ed with symbiotes as well. While Eddie Brock is the new King in Black, he's not forcing the surplus of symbiotes to do anything. Instead, he simply guides and leads them as needed. As a result, Venom #200 from Donny Cates, Ryan Stegman, JP Mayer, and Frank Martin sees Agent Venom discovering that many of the freed symbiotes stayed with their new hosts even after Knull had been defeated.
Basically, this means that there are now more symbiote-bonded humans in the world than ever before, and it's essentially a whole new race of people in the Marvel Universe. Likewise, Flash is seen trying to protect a young man and his symbiote from the group known as the Guardsmen, who claim that they've been authorized to take down any and all symbiotes they can find, being seen as threats. However, this young man begs for his symbiote to not be taken away from him, as it was serving as a cure for his terminal illness. Regardless, Agent Venom takes note of the fear people have after he saves the kid, and it's on par with the levels of fear the X-Men and mutant race have dealt with for years (despite now having their own island nation).
As far as Agent Venom is concerned, it certainly seems like Flash just found his purpose going forward. These new symbiote hosts and their others are going to need help, especially if there are now groups being formed and sanctioned to hunt them out of fear. One can imagine that this particular part of the issue featuring Flash serves as a kind of prologue for the Extreme Carnage series, which will also feature Agent Venom and a plethora of classic symbiote characters alongside Carnage, seeing them grappling with the aftermath of King in Black, and presumedly this new status quo for their kind.
In any case, it's interesting that Marvel is effectively setting up symbiotes to be just as big of a population as mutants or even Inhumans. However, it does makes sense that humanity would instinctively fear symbiotes considering all that's happened. That being said, symbiotes are no longer under the control of Knull, and they're now free to make their own choices. It stands to reason that many of them just want to find an ideal host and live in peace as this young man and his other seemed to have wanted. Either way, it's going to be really interesting to see how a greater population of symbiotes integrates into the larger Marvel Universe, as well as how heroes such Venom and Agent Venom will respond.