I wouldn't call Five eyes very democratically supervised.. It seems there is hardly any oversight at all.

https://www.rnz.co.nz/news/politics/512315/updates-foreign-a...

> GCSB 'failed to respect' minister's control of agency According to the report, the decision to sign the memorandum of understanding regarding the signals intelligence system and host the capability was not put to the minister responsible for the GCSB. Nor was it put to any other minister. "This inquiry found no record of any ministerial briefing or decision, nor any reference to any having occurred. It found no record of the minister having been informed of the matter at all," the report said.