[homecoded]

Good point. But: The library records will have an actual eye witness, though. In that case a real person can confirm that the 'bad guy' got the book personally. That is not the case with online search.

The problem I see is that it makes people easier to frame if 'soft evidence' suddenly becomes 'hard facts'.

Here is a highly constructed unlikely case as an illustration: Suppose, someone sneaks into someone else's house. He performs a few searches on fundamental religious topics and bomb building and plants some large quantities of questionable substances in the garage. Then the intruder tips off the police anonymously. How do you think the home owner will get out of this?

I don't know. I'd be at least a little bit worried.

[ceejayoz]

The searches aren't really necessary in that situation, though. Planting guns and explosives and tipping the cops off anonymously would do the job just fine without a search history. Hell, the cops might consider the lack of search history an indication that the person covered their tracks by using a library computer or something.

[VladRussian]

your best hope in this case is that you'll be tortured and still wouldn't be able to provide the details on the questionable substance - that will prove your innocence.