The online abuse began as soon as my Avengers: Endgame review appeared

‘Nice job on spoilers in your Endgame review. Dick,’ read the first tweet

Avengers: Endgame: ‘You’d think they would, by now, have learnt the message and left behind the useless Hawkeye’

If you’ve had anything to do with cinema and social media over the past decade you’ll know that much prerelease chatter involves the avoidance of what everyone now calls “spoilers”.

Nothing wrong with that. Right? Nobody wants to be told that Rosebud is a sled or that Darth Vader is Kermit’s dad. (Sub, please check this.) You’re a reasonable person. You believe plot points should be revealed with caution in reviews. Good for you.

But the Spoiler Police have been getting madder for years, and the furore around Avengers: Endgame has been extraordinary. The last in the current Avengers series – almost certain to become one of the three highest-grossing films ever – has been shrouded in levels of secrecy that would give the KGB pause.

It was The Irish Times's misfortune that, thanks to some weird glitch, our notice was the first and, for 20 minutes or so, the only article posted on Rotten Tomatoes

Actors such as Brie Larson were flown on to set and asked to deliver a few apparently unconnected lines before, without fully grasping their character’s role in the plot, being hurried away.

The official trailer for Avengers: Endgame has been released, Avengers: Endgame is the grand conclusion to twenty-two Marvel Avengers movies. Video: Walt Disney Studios

As was the case with the preceding Avengers: Infinity War, Anthony and Joe Russo, directors of both films, issued a letter demanding silence from all early viewers. “Remember, Thanos still demands your silence. As always, good luck and happy viewing... The Russo Brothers,” it concluded.

Social media was awash with posts featuring text such as “me avoiding #avengersendgame spoilers” beside gifs of ducking meerkats or a fleeing Scooby Doo.

Then critics saw the film.

Reviewers have always wrestled with the tricky question of how much plot to reveal. Obviously (you’d think) you have to reveal a certain amount. The central premise and general structure of the film are fair topics for conversation. But writers tend to avoid any significant plot turns after the first third and anything from any point of the film that counts as a twist.

If you were, for example, reviewing Jaws, you could happily explain that a police chief, a marine biologist and a salty sea captain end up hunting down the shark. They don’t set off until quite late in the film. But that’s the central premise. And so on.

Such was my approach when reviewing Avengers: Endgame. Obviously, I didn't say who died. But I laid out a rough sketch of the key scheme and made some cracks about how that rubbed me up. There was nothing from late in the film. There was nothing you could remotely call a twist.

No matter. All hell didn’t actually break loose, but a pocket Hades did cloud around my Twitter account.

It was The Irish Times's misfortune that, thanks to some weird glitch, our notice was the first and, for 20 minutes or so, the only article posted on the review aggregator Rotten Tomatoes. Eleven minutes after the review embargo was up, the following arrived: "Nice job on including spoilers in your Endgame review. Dick. Not to mention breaking review embargo. I hope you get stripped of your credentials."

Sniggering as I imagined myself an Alfred Dreyfus – dragged towards the parade ground where my epaulettes are ripped from my shoulders – I wrote back to observe that I had broken no embargo and that there was nothing there you could call a spoiler. I may as well have written in Swahili as outline the well-worn approach described above.

“Spoiling something that would only be known through unofficial set photos is spoiling,” he replied.

Let me translate. This means that, for a portion of the audience, a "spoiler" is now any piece of information that does not appear in the trailer or in other publicity material. "Anything about the story constitutes a plot spoiler," Anthony Russo told my colleague Tara Brady before the release of Infinity War last year.

One person noted: 'I can careless about what some corned beef eating Irishman has to say they're probably mad St Patrick or Bono isn't in the Avengers lol'

There were more tweets. The following day I received a (reasonably polite) Facebook message that explained what I should have been doing all these years before concluding: "please improve your review writing skills". Somebody else – who didn't actually tag me – noted "I can careless [sic] about what some corned beef eating Irishman has to say they're probably mad St Patrick or Bono isn't in the Avengers lol."

All of this was most amusing. The notion that the critical community should bend to an absurd rule – Everything Is a Spoiler – that only emerged within the last decade is not worth taking seriously.

There have always been sensible people who, eager to arrive fresh, refuse to read a notice until after they have finished the film, play or book under discussion. Most critics don’t care for star ratings, but those grades do, at least, allow such folk to get guidance before reading the text. This seems a sane way for all to behave.

Anyway, these conversations only kick up when discussion turns to the colossal blockbusters. The spoilerphobia works as a promotional technique for the studios: the mystery stirs speculation among the same people who, paradoxically, pore over trailers for any signs about coming developments.

Nobody expected critics to be so cautious with plot points when discussing Green Book, A Star Is Born or The Favourite. Away from the enormous franchises, the same rules as ever apply. They always will.

As the chatter bubbled on, a suggestion emerged that there may be nothing we can do to satisfy the Spoiler Taliban. Late in the week, somebody on Twitter took issue with a user merely saying that he had liked the film. “You know what would be really cool? Not giving takes on a movie that isn’t out yet,” she replied.

The original poster expressed bafflement that he was not allowed to even say that Endgame was good. “Yes. That means I now have the expectation that they didn’t f**k it up,” she hit back. “l.;;How you feel about something is just as much a spoiler as saying who dies.”

Don’t even think about Iron Man. Don’t look a picture of Black Widow. That now counts as a spoiler.