If you're on the Internet and you're seeing ads, you're doing something wrong. Use a decent browser that supports Ublock Origin or use a PiHole instead.
Advertisement networks are a legitimate security threat because they don't vet their shit or even properly secure their own damn infrastructure consistently.
Build your own? Given the constraints, that might actually be more viable than you'd think. Keep in mind, you could disable or even block radio transmitters to comply with whatever your environment is.
You know what would be really cool? Mbin support!