Whilst it's certainly a scam to do with advertising [0], I doesn't look like there's any evidence that the scam has anything to do with 'stealing' anything from network / network traffic:
> Facebook has several mechanisms in place to protect your account. We make every attempt to work within the these constraints. In order to keep your account from being locked we use a small device called a Raspberry Pi. This device allows us to connect to Facebook advertising APIs from your home network and avoids the hassle of your account being locked due to unfamiliar activity. Learn more about the Raspberry Pi below.
> Facebook has several mechanisms in place to protect your account. We make every attempt to work within the these constraints. In order to keep your account from being locked we use a small device called a Raspberry Pi. This device allows us to connect to Facebook advertising APIs from your home network and avoids the hassle of your account being locked due to unfamiliar activity. Learn more about the Raspberry Pi below.
[0] https://www.reddit.com/r/Scams/comments/2vd1g8/scam_rentyour...