Bradley Ross,
I assume that you are writing about this. I haven't actually played the game.
The article listed several possible approaches to spoofing and detecting spoofing. In response to what you mean by "effectively", the answer is "it's complicated". If the attackers keep creating new accounts, it would seem that somebody could always do some damage. HTTPS wouldn't help since you are altering what your own device is sending rather than altering the data stream.
The techniques that Niantic can use are definitely limited by cost. If the cost becomes too great, the game will vanish. Most of the items in the article seem valid, although I would add a few others.
If you create a new account, use an e-mail verification with a captcha built into the mail message. This would at least make it more difficult to create hundreds of e-mail accounts. Without this, none of the other methods would appear to be workable. You could do verification using both e-mail and phone numbers. (Phone numbers are harder and more expensive to get in large quantities than e-mail addresses.)
Another approach would be to plant some sort of verification into the game that could be triggered remotely. For example, you might have to take an action in response to a message, e.g. "Click on the brightly colored cube". If the game works as I think it does, you could have indicators planted in the field that would be part of the message/response. You could ask the player to face east and take a picture.
As I see it Niantic has a few options.
Do nothing and hope that the players stay with the game.
Develop countermeasures and incorporate them in the system. This could impose costs and limit playability.
Use the game as a testing ground for new software tools to prevent spoofing and lying and then sell the results of the research. (There is one web site with a "20 questions" type game that is doing exactly this. They are using the site to test methods of detecting duplicity in on-line questionnaires. They make software for on-line questionnaires.)
Take legal action against those who provide tools for cheating on games. I doubt if this could be done.
source: www.quora.com