Porn isn't taxed. Effectively then, according to some economists, it's federally subsidized.
Pornography is enjoyed by many people, but it comes with a very real social cost: it can break up families and perhaps even become an addiction, which are profound losses of productivity.
This is a societal cost, and unlike tobacco and alcohol, users pay no taxes to offset their damage. In essence, the porn industry benefits from an indirect subsidy because there is no user tax. Oh, sure - implementing a user tax might raise privacy concerns.
I hate to break the news, but we're in the 21st century now, and there is little - if any - privacy any longer. Your phone usage is tracked, and cameras are everywhere. Your grocery store knows exactly what you've purchased, and when. You may think that because you use TOR or other anonymity tools, you're cool. Guess what, even I can track you.
If you're a porn user, you can be tracked, you can be found, and that means that you can be taxed. Now, what's that got to do with so-called subsidies to so-called fossil fuel companies like Shell (never mind that oil is not a fossil fuel)? Well, like porn users, the suppliers and users of so-called fossil fuels aren't taxed because of the emissions resulting from combustion to produce energy. Naturally, these complainers lump coal (a fossil fuel) along with oil and natural gas (which are not fossil fuels) to arrive at the conclusion that fuel providers are getting over five trillion dollars in subsidies.
That argument is ridiculous on its face: extraction companies purchase lease agreements to produce a product, and much like the porn industry, nobody is required to use the product. The absence of a user tax does not equate to a government subsidy for the product(s) in question.