A Bingo Troll is a person who posts irrelevant or off-topic comments in an effort to disrupt or antagonize other users. They may also deliberately post low-quality content in an effort to make the site look less reputable.
Bingo Trolls are often considered to be negative influences on the site and can sometimes lead to a decline in user participation.
While there is no definitive definition of a Bingo Troll, most users would likely identify someone who follows these tactics as such. In short, a Bingo Troll is a user who uses online forums and social media to harass, irritate, and generally disrupt others.
While they may have benign intentions at first, over time they can have a negative impact on the user community and site performance.