Look at the details to find the devil
Something I remember reading about this was a statement that the ISP retained data was 'simply' a record of which website you had visited, not any details of what you looked at.
However, in the past there have been court cases where it's been stated in evidence that (as an example) the accused had performed Google searches about how to kill someone with paraquat. The search terms do appear as part of the address string and I assume they are stored by the ISP in totality. So, we are immediately lied to.
(It's possible that the police went to the trouble of contacting Google and asked them to search their server records for requests from a particular IP address. I doubt that however.)
So, your local police will know that you've been searching for haemorrhoid cream and the clerks at the tax office will know that you need snug fit condoms.
As I've asked (rhetorically) before; what are the penalties for unauthorised searching of ISP records and for misuse or abuse of the information in them? I suspect there are none.