  This study discusses the Review Bomb, a phenomenon consisting of a massive
attack by groups of Internet users on a website that displays users' review on
products. It gained attention, especially on websites that aggregate numerical
ratings. Although this phenomenon can be considered an example of online
misinformation, it differs from conventional spam review, which happens within
larger time spans. In particular, the Bomb occurs suddenly and for a short
time, because in this way it leverages the notorious problem of cold-start: if
reviews are submitted by a lot of fresh new accounts, it makes hard to justify
preventative measures. The present research work is focused on the case of The
Last of Us Part II, a video game published by Sony, that was the target of the
widest phenomenon of Review Bomb, occurred in June 2020. By performing an
observational analysis of a linguistic corpus of English reviews and the
features of its users, this study confirms that the Bomb was an ideological
attack aimed at breaking down the rating system of the platform Metacritic.
Evidence supports that the bombing had the unintended consequence to induce a
reaction from users, ending into a consistent polarisation of ratings towards
extreme values. The results not only display the theory of polarity in online
reviews, but them also provide insights for the research on the problem of
cold-start detection of spam review. In particular, it illustrates the
relevance of detecting users discussing contextual elements instead of the
product and users with anomalous features.
