I had a situation recently where I was accused of stealing another window cleaning business's customers, and additionally I was warned not to be seen working there again. I politely but firmly replied that I was going nowhere and, rather than stealing his work, told him that they had approached me, which is in fact true.
I have no knowledge or interest in what they charge, and the customers who approached me hadn't told me that they had used this other company until after I had cleaned for them (they are not questions I would ask).
Since then, I have picked up a fair few of their ex-customers. They all say the other company's attitude stinks and they are unreliable anyway, despite having an all bells and whistles sign written van, whilst I have an old plain white Fiesta van, but provide the service and have a good business relationship with these customers.
So do I feel bad about these guys losing their work to me? Not all. After trying to 'run me out of town', they are actually doing it to themselves.
John