In some cases, Black Mirror barely moves into the future at all. The very first episode is a good example - it's based around a kidnapping and the use of social media to make public demands, something that is possible today. Other episodes make use of advanced technologies such as direct brain interfaces for gaming or ubiquitous personal life recorders. Those may not yet exist, but it's not much of a stretch to see such things developed in the near future.
Most of the episodes are either disgusting or horrifying, dealing with everything from murder to sexual deviancy to genocide. If that's all there was to Black Mirror, I wouldn't have bothered with more than an episode or two. Below the obvious disturbing theme, though, there are always ethical questions to consider.
For instance, in one story the government secretly installs back-door access to an environmental project that is used for warrant-less surveillance. It goes well for a while, even being used to solve or prevent crimes, but eventually that access is hacked and used in a killing spree. Giving law enforcement the ability to circumvent security, despite the risk of misuse...sounds like a question that our society struggles with today. Pretty much all the Black Mirror episodes have a similar kind of ethical theme that prompts thought about current events.
It's probably not a great idea to binge-watch a bunch of Black Mirror episodes all at once, because they're all pretty disturbing. I found it well worth the time to go through the series slowly, though, and think a bit about the ethical questions raised in each episode.
