How does one report a blatant spoofer?
Go here: https://ingress.com/support then click the icon at the bottom right. Report inappropriate gameplay.
I can't say I've had good luck with that route-- a couple of weeks I reported an obvious spoofer leveling an account in my city. I was pretty sure it was a spoofer based on the account playing in two closed parks the day before. This time were two blocks away from me and heading my way so I just parked my car and waited. They passed right by me and captured/linked all the portals but nobody was there. They couldn't have hit those portals without being on the main road, and it was 1 a.m. so essentially nobody was out. They turned a corner and I went to the portal that the account was linking and fielding from. Nobody was there. When I smashed the portal the account quit playing but showed up in a city 800 miles away a day or two later.
Two nights ago the account spoofed up a BAF over a largeish city after upgrading and presumably farming keys to a BGAN-only portal. They got reported again and this time the account got banned.
As @Hosette said, report on the support site, or in-app under "Settings" - "Report a problem"
Best to keep your report brief and on point.
You do not need to include comm logs, maps, screenshots, video or anything like this.