Wow. I'm amazed by stories like.

I'm so naively the "take the high road" kind of guy, that I just assume everyone (or every company) should just do the right thing. Stealing customers in this way from a competitor, I have no ability to rationalize such an action.

And this kind of makes me scared, like if I were to ever own a business, I just know I'm swimming with sharks with no ability to defend.

I believe your story, but it's just crazy to me. Go earn a customer's business in a legit way, not be stealing data from a competitor.