MoviePass exploded in popularity over the holidays, reaching over one million concurrent subscribers in December. With a $9.95 monthly subscription fee, that adds up to be a pretty nice chunk of change for the company.

For the unaware, MoviePass is a service that allows subscribers to watch as many movies as they'd like in theaters for a single monthly fee, making it ideal for weekly or even daily moviegoers. There's only two caveats of note: you can't see the same movie twice and you can only watch one movie per day.

Due to MoviePass' recently popularity surge, the company has struggled to keep up with demand for their service. To help offset some of their growing costs, the company has announced plans to invest in film creation to boost revenue.

Theater executives have come out against the service, calling it "unsustainable." This belief might prove true if MoviePass' latest decision is anything to go by - many MoviePass subscribers have reportedly found that their service debit cards no longer work at a "small handful" of AMC theaters, including some of the most popular locations.

MoviePass took to Twitter to respond to customer complaints but their statements haven't shed much light on their reasoning:

Some MoviePass subscribers, suspecting foul play on the part of theaters, approached AMC about the situation. However, the theater chain claimed they haven't been restricting the use of MoviePass in any way: