Can I legally videotape my neighbors?

Question Details:

My neighbors do hard drugs on their side porch and I was wondering if it was a violation of their privacy if I video tape them from the interior of my house. I would like to have them evicted as I don't want to live next door to **** users but it's my word against theirs unless I can get evidence for the police. They also have two young children and I think Child Protective Services should be notified in case their is any abuse going on. Important Notice