A review bomb is an act of aggression, a step meant to send a message of extreme discontent with the actions of a particular developer.

The term refers to organized campaigns to give games on Steam low reviews as an act of protest, a situation that has been become so common Valve added histograms to make it easier to see which reviews are likely to be legit and which are part of a likely review bomb. Steam now also separates “recent reviews” from “all reviews” when saying if overall reviews are positive, negative or mixed to make the outliers easier to spot.

And the data is not subtle. Campo Santo co-founder Sean Vanaman tweeted the following on Sept. 10, a reaction to PewDiePie’s use of a racial slur during a recent stream.

We're filing a DMCA takedown of PewDiePie's Firewatch content and any future Campo Santo games. — Sean Vanaman (@vanaman) September 10, 2017

Using DMCA complaints in this manner is perfectly legal, but many disagreed with the potential implications of this rather unusual move. Enough people were upset that a review bomb was aimed at Firewatch, Campo Santo’s successful first game.

We can see this process begin on Sept. 11 with Steam’s new histogram. First, let’s take a look at all of Firewatch’s customer reviews to date:

The majority of reviews were posted when the game launched, with a reasonable number of negative reviews posted at the same time. That makes sense, as Firewatch isn’t a game for everyone. There are a number of review spikes throughout the life of the game, likely due to Steam sales. And then the review bomb pops up at the right end of the graph.

Steam automatically isolates and shows you the information for the suspected review bomb, which is nice.

There were 215 negative reviews the day after Vanaman posted his tweet, with fewer but still substantial numbers of reviews for the next few days before the bomb rapidly tapered off. This wasn’t an issue people felt that passionately about, it seems.

Another interesting point is that there 303 positive reviews on Sept. 13. Once word of the review bomb got out, fans of the game came out in larger numbers, at least on that date. Critics of Campo Santo attacked the game, and fans fought back. But neither group was very large when compared to the overall sales and reviews of the game to date.

And then there’s Playerunknown’s Battlegrounds.

The customer reviews are “mixed” overall, according to Steam, but there’s a hell of a review bomb going on. The bomb started due to advertisements shown to gamers in China, and people are angry.

Players posted 6,789 negative reviews on Oct. 1, the bomb’s most active date. The negative reviews are still being posted, with 4,731 posted on Oct. 3. The last bar represents the reviews today as of the time of this writing.

Do these bombs do anything?

It’s hard to say without having access to sales information, but the negative reviews rarely have anything to do with the game itself. Sometimes they happen due to the actions of the developer, and other times they’re posted to draw attention to a particular problem in a game’s update or some other unresolved issue.

In other words, review bombs take place not to talk about the quality of the game in any kind of general sense, and they’re rarely posted to give any information about whether or not they should buy the game itself. The most popular use of review bombs is to send a message about one particular issue or perceived wrongdoing on the part of the developer or publisher.

They do bring attention, both good and bad, to the issue that’s angering those who are posting the negative reviews. These bombs are talked about, which means the actions that the bombs are meant to protest get more publicity. They are successful if judged only by the attention they gather, which means they are likely to continue unless Steam takes other measures to limit their efficacy.

We can debate the “proper” use of customer reviews, but their utility for sending this kind of message is hard to argue. It has been interesting, anecdotally, to hear so many players defend review bombs due to the fact they feel like there is no other way to get the attention of a developer.

They may hurt sales, or they may make the mob seem sinister, but they do gather that one resource very well. They do get your attention.