Growing up in Toronto (Ontario, Canada) there was a kerfuffle in the press when a television cable provider was taken over by Rogers and ‘I thought, what’s the big deal? It’s not like we had a choice anyway’.
Islamically, this is the wrong way to think. If something is a “natural monopoly”, it’s a good indicator that it should be commonly owned. These are things that require the use of the common lands, skies and waterways. Consequently, private enterprise should not be involved.
Furthermore, Prophet Muhammad (saw) said:
"No one Monopolizes except a wrongdoer." [Muslim]
"Whoever strives to increase the cost (of products) for Muslims, Allah, the Exalted, will seat him in the center of the Fire on the Day of Resurrection." [Ahmad and al-Hakim]
Consequently, monopolies are not allowed in Islam and it is a crime to increase the price through monoploistic tactics.