Does anyone know what this mysterious device is?

[rules&rulers]

Put a similar box on your own property.looking at them.

 

[DaveHerns]

Neighbour has CCTV cameras covering his property which he can access on his mobile and he says there's a speaker so he can remotely tell people to clear off. Maybe it's the speaker.

 

[Ian H]

Neighbour has CCTV cameras covering his property which he can access on his mobile and he says there's a speaker so he can remotely tell people to clear off. Maybe it's the speaker.

"Get back yer ******* or i'll break yer legs"