You're asking the wrong question. At whose expense am I sauntering down the street? Depends on the situation.
OK, at whose expense are you sauntering down the street, and how does this sauntering apply to " possibly enrich themselves at the expense of others"?
Who owns the raw material? You control the private keys; you don't own them.
OK, then who owns the raw materials, and who owns the bitcoins I control?