DataLog is used to verify smart contracts. I don't know any specific examples of prolog used in the industry, though I am sure there are a few. Probably, there are expert systems implemented with prolog that are still used.
Logic programming in general has a few usages, the unification algorithm is used for pretty much every type system. Also, it is quite good for verification systems. For example, I know some symbolic execution systems implemented in OCaml.
What happended to "Don't feed the trolls"? I thought it's shared expirience that giving attention to trolls like that only gives them motivation to keep on going. Ignoring them is the only way to stop them from spamming.