Hi there,
The TL;DR is that somebody is abusing the BGP protocol to be in a position where they can intercept the miner traffic. The concerning point is that they seem to be having some degree of success in their endeavour and earning profits from it.
I do not understand the impact of this (I don't know much about BGP, the mining protocol nor anything else, really), but I thought it might be worth putting it up here.
Ta,
Pedro