Have have two CCTV cameras pointed at my neighbors house?

I could write a novel on the things they've done to my house and property. The cameras at this point are not fixed, are inside my own home pointing through windows. The neighbors have several foster children to supplement their welfare getting lifestyle. They practically live in squalor, which will no doubt affect my house price and that of other neighbors. I would like them gone obviously and don't care if they know my cameras on on a live feed at their house. I'm a little worried they may try putting a case against me for spying on their kids in their yard. Today I heard lots of yelling at a 7ish year old boy they foster.. I eventually heard him crying profusely, which is very unlike him. So it feels as though the cameras are even more warranted now that I think about it.

People may say what they do in their yard is none of my business, but what has happened in my yard, I have never received an apology and damages. Even after a car was vandalised by older children who visited the house, firewood and tank water stolen, my house egged. windows mysteriously smashed, bottles smashed on my roof and used diapers in my mailbox! They are non productive slovenly pathetic animals.

Do you think they can cause legal trouble with my cameras?