AOL has released search usage data for a selection of AOL users in the period between March 1st and May 31st, 2006. There has been some controversy regarding the insufficient anonymization of the search data, and some of the users have been identified from the data.
The web site aolstalker.com gives a per-user view of the search data, in addition to the possibility to see who, if any, searched for a given term.
Searching for "twingine" revealed that two of the AOL customers sampled in the data used Twingine in the time period of the sample.
A note on privacy: Twingine is run by an individual, not a business, on a personal computer in a private residence in a country with strong privacy laws (Norway). As such, the data is much more protected than if a corporation was responsible for the hosting or operation of the service.
Yahoo! and Google have however been subjected to subpoenas in the past for search data. Google refused to comply.
The Electronic Frontier Foundation have more information on the AOL case.