I think "monopoly/not monopoly" has always been the bad criterion to judge this problems (when I say "always", I include the "Sherman Antitrust Act" of 1890).

I think "monopoly/not monopoly" has always been the bad criterion to judge this problems (when I say "always", I include the "Sherman Antitrust Act" of 1890). The problem is more generically when some company use is its power (company size in a market as buyer or seller, technical possibility to block competitor, etc ...) to disable competition instead on fighting on quality and price of their product and services.