I can think of 2 potential reasons but neither seems satisfying. The first would be state agencies testing attack vectors in real life. Would suck to send out an agent who commits their crime 100% flawlessly only for them to get caught by some unsecured doorbell or other random internet device. The second would be attempts to force increases in security through intentional hacks and sabotage.

Although if someone can think of better reasons I would love to hear it.