It's not that it will be impossible to detect (they probably will be for quite some time) as it's about nature of dissemination - you first see fake, and only i

It's not that it will be impossible to detect (they probably will be for quite some time) as it's about nature of dissemination - you first see fake, and only in its echoes you possibly see the truth. Now, problem is, if fakes are easy to make, there'll be more of them, particulary if they generate impressions and spread faster than rebutals. And as space of fakes is infinite compared to space of truth, with advanced tools, it can be concocted in such a way that falsifying it might be lengthy process. And, in some cases there, it may be too late.