I don't know about the US, but so-called "test purchases" are an extremely well-known practice in the UK and it's not the least bit controversial to suggest the

I don't know about the US, but so-called "test purchases" are an extremely well-known practice in the UK and it's not the least bit controversial to suggest they happen - and everyone knows it if they've ever worked on a bar. I know someone who lost his job for failing to ask for ID when the customer was a test purchase.