⭐ Best answer
Assume it's an accident first, because it usually is. Most doorbell and porch cameras get installed by someone who never checked the actual field of view.
1. Mention it in person or by text, friendly, factual: "Hey, just so you know, your camera looks like it catches part of my yard too — not a big deal, just wanted to flag it in case you didn't realize." That framing gives them an easy, non-defensive way to just adjust it.
2. Give them a chance to fix it before assuming the worst. Most people will just re-angle it once they know.
3. If it doesn't change, or they get weird about it, check your local laws — recording someone's private space (not just incidentally catching a yard, but actually surveilling into windows or enclosed areas) can cross into actual legal territory, and that's worth knowing regardless of how the conversation goes.
Leading with the friendly version first solves this nine times out of ten, and keeps you from starting a neighbor war over what's probably just a cheap camera pointed slightly wrong.