这种事情我也遇到。主要作用是吓阻，装了摄像头后要在醒目的位置贴上牌告，本房有24小时摄像头监控。见：

https://www.amazon.com/Sheenwang-Property-Trespassing-Surveillance-Aluminum/dp/B07X8MMZ1V/ref=sr_1_2_sspa?crid=2PL00LA8A45J9&keywords=security+signs&qid=1674150644&sprefix=security+%2Caps%2C80&sr=8-2-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzRFQxWTBSSk0wMjBYJmVuY3J5cHRlZElkPUEwMzAwNDQwMTA5MlNZUkxZQzAyVSZlbmNyeXB0ZWRBZElkPUExMDE1OTc1M1JFUkVaWFRPMjIxNyZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=