Quote from: cocopopcorn on September 12, 2019, 08:16:12 AM

--snip--
How do they know a bitcoin wallet is issued by coinbase?

Probably because unspent outputs funding those addresses were used together with unspent outputs funding other addresses... This way addresses can get linked together. If you have positive confirmation one of those addresses that are linked to other addresses belongs to coinbase, you have confirmation all addresses linked to this confirmed address belong to coinbase.

Quote from: cocopopcorn on September 12, 2019, 08:16:12 AM

Are they issued in blocks much like an ISP will have IP's in a block/range?

no

Quote from: cocopopcorn on September 12, 2019, 08:16:12 AM

Also i assume all address must already be created (there is a limited (all though vast) amount of potential addresses) so how are they issued/ claimed?

no... Addresses are not pre-created

Quote from: cocopopcorn on September 12, 2019, 08:16:12 AM

If this is so why are some wallets 'unknown' I did think maybe trezor or ledger and the likes may be 'unknown' ... but surely they must of been issued too so why are they unknown.
--snip

All addresses are 'unknown', it's only when you link a real life person or a company to one address, people can use data analysis to find other addresses that can be linked to the address that was 'de-anonymised'

I'll update this post in about 30 minutes and try to give some theory as to how this works exactly... check back in 30 minutes

Some theory.... greatly simplified
Your wallet generates either random private keys, or it generated 1 master private key randomly and it derives private keys from this master private key (HD wallet).
The private key is used to generate a public key. The public key is hashed and the results of the hash is the address.

When you pay somebody, you use an unspent output that funds an addres whose private key you own, and you create a transaction that basically says "i use the unspent output x from transaction y to fund address z" and you sign this transaction with the private key belonging to the address that belongs to you.

At this point, this transaction is pseudo-anonymous. As long as nobody knows you're the owner of the address, everybody can see the transaction, but it's unknown to anybody.

How can addresses be linked together? Well, for example, your wallet holds 2 funded addresses 1AAA and 1BBB, 1AAA is anonymous, but you've made a forum post indicating 1BBB belongs to you...
If you create a transaction that basically says:
"i'll be using unspent output x from transaction y that funded address 1AAA AND i'll be using unspent output a from transaction b that funded address 1BBB to fund address 1CCC", everybody can now see address 1AAA and 1BBB belong to the same wallet, so everybody now knows 1AAA is no longer anonymous