An e-mail from anonymous

I came home from work late on Thur. night and my wife was upset about something. She didn't really tell me what was wrong with her at first. She wanted to talk to me about how my day at work went. I worked a double shift that day. When we went to bed that night she told me what was wrong. She received an e mail from someone that was using an anonymous address. The message said that the person was upset about how she was acting when a certain customer would come into the store and that she should not act like that in a small town. They also told her that they new she had opened a bank account in her name. They said that if she didn't tell me about the account that they would because they have both our e mail addresses, work addresses and phone numbers. This struck me as really odd to say the least. It really upset her a lot. She was crying about the e mail and how it screwed up her day. She told me that she did open a bank account in town. It did not surprise me as we talked about her opening a account for her to use specifically for her business. It is a way of protecting ourselves and keeping business money separate from household money for tax reasons. As of today she has not received another e mail from this person.
What pisses me off about this is that we don't know who this person is and what their motive is. How does this person have all of our contact information? It just don't make sense.
So this Memorial day weekend my wife's sister is here for a week. We went to the lake for the day yesterday. It was pretty fun. The kids went swimming and we had a good BBQ dinner. We got home late and watched a John Wayne movie before bed. We haven't done much today except lay around the house watching TV and doing laundry. My wife does appear to be happy that her sister is here for a week but she just won't talk to me. My sister-in-law did read this blog when she got here Fri. night and said this is not the sister that she grew up with.