Remember the adage that there is no such thing as a free product. If you are not paying for the product and service, then you are the product and being monetarised in some way. That could be by targeted ads inserted into your internet stream, or search details and records of sites visited being recorded and sold on.
Your personal data should be safe enough, as will the contents of any information uploaded and downloaded, because it should be encrypted. But search records and a record of sites visited is a commercially valuable product when extended across thousands of people.
Neighbourhood watch areas tend to operate in middle class, reasonably affluent neighbourhoods populated by people with aspirations. An ideal target for organisations that want to sell you stuff. Poor neighbourhoods tend not to bother with neighbourhood watch schemes and the very rich live in gated communities and don't give a damn.
It may not be a scam, but be sure you will be paying, one way or another.