Online Drift happens in online social media platforms - where you start of as a centrist - but gets slowly pushed to one extreme or the other. All online platforms will serve you content that you like. There is a progression for this - it will start of as mild - but it will become more and more extreme over time. This is to increase engagement.
This happens due to emotionally engaging content. Even if you are against a specific content, you are still emotionally engaged due to it.
There is also an Echo chamber effect - you'll only be shown content from people who more or less think like you.
Safe spaces can become breeding grounds for toxicity as they tend to ban people with opposite ideas. Soon you'll be able to talk anything about the "opposing" camp as there is no one to say you are wrong.
This is an unintentional emergent property.