[figbucket]

You're right however part of the freedom comes from choosing where your bubble ends. Consciously choosing where you filter what you allow into your bubble be it NYT front page or fox news etcetera.

>if your current interests and beliefs act as filters, then how will you ever develop new ones?

This partly comes down to being another personal choice and also consider that many things are linked in a way that enables you to develop new interests and beliefs.

One example of this is Wikipedia. Starting from pretty much any point of interest, you can find a great depth of chain linked resources to information you can choose to read and allow influence your interests and beliefs

>or, coming down to the core topic of this site, how will you know your audience... ?

Best to start by building what you know however I realise that's unrealistic. After that you just accept that you can't filter everything because somethings you want in your bubble have baggage. "Every rose has its thorne" as the saying goes.