Lather rinse repeat with a better choice of address...
2001:550:3ee3:f329:102a3:2aff:fe23:1f69
This is in the ARIN region...
Actually it's not a valid address at all, because it also has a typo. one might assume with a typo that the most significant bits are probably correct but potentially compounding errors doesn't sound like a good idea.
Yes... Should have been 2001:550:3ee3:f329:02a3:2aff:fe23:1f69. Not sure how the extra 1 got in there.
It's from within a particular ISP's /32.
Has that ISP delegated some overlapping fraction to another ISP? If so, it's not in whois. Have they delegated it to an end user? Again, if so, it's not in whois.
Same for 2001:550:10:20:62a3:3eff:fe19:2909
I don't honestly know if either of those prefixes is allocated or not, so maybe nothing's wrong in this particular case, but if they have been delegated and not registered in whois, that's a real problem when it comes time to get a search warrant if speed is of the essence.
If you're asserting that cogent is not swiping their delegations then do so. they have certain obligations as an LIR under the policy under which resources were delegated to them. future prefix assignments will clearly require that the demonstrate utilization much as they are required to in ipv4.
I'm making no assertion about cogent whatsoever. Since I don't know whether those addresses I chose at random within the ARIN region happen to be delegated or not, I have no ability to determine whether they should be registered as delegated or not. I said this in the above paragraph you quoted. I was attempting to demonstrate the potential problem, not point to an extant example as I do not have an extant example handy, though I suspect such do actually exist. Owen