>" who owns it? (keep in mind you don't own your credit card, the issuing company does)
I would say that you do. And you keep it indefinitely.
>"who pays for it?
I think you would. But it's cheap- the animal implants are like $20.
>"who personalizes it?
>" who is responsible for the data inside the implant?
As I understand it, most of these chips would not contain the data itself- only ping a number that would then match to databases maintained by different people for different purposes. Like your credit card would have one data base, your hospital another. Really no different than it is now.
>" who has the right to read, erase, write, update data in the implant?
>" who is responsible in case of malfunction?
Failure would be unlikely- especially for a simply number pinger, but I would say the chip company should replace it if necessary.
>" and even most important: where will Visa MasterCard and a couple others print their logo?
Well, it doesn't have to be on the chip you know- they could tattoo it on your forehead!