I use Cloak to protect my Mac and IOS devices when surfing the internet from WiFis outside of my home. Inevitability, I receive alerts from Google advising me some unauthorized person attempted to log into my Google account. These alerts were driving me crazy and I changed my password every time I received one. Anyway, I came across this blog entry on Cloak's website. It explains what might be happening. For those of you using Cloak it might be helpful to you. 