How to find out who owns a bitcoin address?

Could you please elaborate on the complexities involved in determining the owner of a Bitcoin address? Given the pseudonymous nature of Bitcoin transactions, it seems like a challenging task. What methods or tools are typically employed to gain such insights? Are there any legal or ethical considerations that one should be mindful of when attempting to uncover the identity behind a Bitcoin address? Furthermore, what are the potential limitations of these approaches, and how reliable are they in practice? Your insights would be greatly appreciated in understanding this intriguing yet challenging aspect of digital currencies.