I was in the US embassy this week applying for a visa. I declared my US DWI charge on the application, and had to go through various hoops becaue of this.
Apparently the question on the back of the visa waiver form asking if you have committed 'moral turpitude' etc., or crimes leading to sentences of 5 or more years in aggregate ... pretty much = 'have you committed any crime ever?'. This was explained to me by an embassy official. I wonder how many people know what 'turpitude' means!? It is a word that probably hasn't been commonly known in England for a century, two, or more.
When I asked why it was US immigration queried my old record, always let me in, and never told me I should not use the VWP but should get a visa, she suggested, in as many words, 'they probably have bigger fish to fry'.
Given 1 in 3 UK citizens are meant to have a UK criminal record, this means none of them are eligible for the VWP. But if this was enfoced and all these people had to get a visa (truly painful process), I expect the UK tourist industry to the US would collapse overnight.