I use them frequently but I'm skeptical of their "private" claims.

I asked one of the DDG ChatGPT bots about some error output from a program and apparently forgot to redact a URL. I found the DDG bot trying to access it about half an hour later. It was a long and randomly generated alpha-numeric subdomain and the conversation never discussed the URL or anything related to it- it was simply buried in the pasted error output. I think this was even before the DGG bots had web search capability. I was thoroughly spooked.

Interresting, Have you done any Møre testing trying to trigger this behaviour? If it is semi konsistent or even just alone it makes a god case to switch.