I found a mobile (or a SIM card). How can I get it back to its owner?

Lost / stolen mobile phone

Do I have to re-activate and register the new SIM card in case of loss or theft?

What is my PUK Code?

SIM card

I've lost my SIM card. How do I get a new one?

How do I know which Sunrise multicard SIM card is active at present? 

How can I activate my SIM card?

I would like to block my SIM card. How do I go about doing this?