I discovered a vulnerability in one client's infrastructure which could cause an outage plus data loss. When pressed for a 1-off cost calculation the client agreed it could cost them upwards of £1 million each time, so I proposed a remediation plan which would have cost under £100k.

They turned it down, as £1 million was below their lower risk threshold - they had bigger risks to set their teams on.

But **a valid risk decision by the business is a correct answer** to go back to a security team with, so this was fine.