A new family moved in the house opposite about 6 months ago, it's a single mum and her kids. There have been no problems so far, the only thing we have noted is that on a couple of occasions we've heard her screaming & swearing at her kids, it's loud enough for us to hear from outside while she's inside with windows closed and DH and I were both quite shocked.
The way our houses are laid out means that although its opposite its not actually 'over the road', so the front of their house is really close to ours and we can see their comings and goings from our living room window while we're watching TV.
Today I've seen the local drug dealer do a quick stop off at her door with his gang mates. It was very obvious and he didn't try to hide what he was doing. He's only young but he's a nasty piece of work and thinks he rules the area. Him and his gang are the cause of pretty much all anti social behaviour in the area.
It's now made me put 2 and 2 together and remember a number of other times I've seen people do quick stops at her door, and I've seen her popping out on her own and then back again within minutes. So I'm now wondering if these were drug related.
I know it's none of my business what people do behind closed doors. But I don't want these types of people (the local drug dealers and gangs) having a reason to regularly be outside my house. We had a lot of problems with the previous tenants who moved out last year so I feel like I am just on high alert but I really don't want this brought to my doorstep 
I also feel uneasy at the thought of her kids being in this environment. DH and I had spoken about her shouting etc. and questioned whether there was anything we should/could do about it or if we were overreacting. As we'd only heard it a few times we didn't do anything, but now with this thrown into the mix I'm not sure if there is something we should do?
Has anyone ever experienced anything similar? What did you do?