Search engine optimization (SEO) is a set of practices employed by people who make websites intended to make sure that the websites show up early on in the search results on Google.
Because it is directly responsible for determining which things show up in which searches, SEO holds danger primarily for the people doing the searching. If they are misled by someone who is good at SEO but is engaged in, for example, making a batshit version of Wikipedia about whether or not things are dangerous, they may encounter nonsense information that doesn't really help them at all.
On the other hand, for the people who do it, there are some inherent dangers in attempting search engine optimization. In particular, these dangers are mostly related to how boring and time-consuming good SEO can be. Also, good SEO leads to more traffic, which might make the website owner's hosting bills go up.
These dangers are counterbalanced in some regards by SEO's benefits, though—if you're really good at it, you might be able to make some money from ecommerce or advertising.
Because it can waste a lot of your time or show you nonsense on the internet, we consider SEO to be kind of dangerous.
