FindUSA was a very popular online service to help you find missing relatives and old friends. You could search for living or recently deceased Americans. The searches returned a lot of information, such as full name, date of birth, addresses for the past 30+ years; property records; court records; links to every person who lived at those addresses for the past 30 years, and much more. Typical reports provided links to individuals, their parents, spouses, and adult children. Apparently the service was a bit too successful and too powerful.
Citing concerns about privacy, FindUSA is being removed from public access. The company states that a business decision was made to discontinue the FindUSA database service to libraries effective immediately. Apparently the database will still be available to private detectives, credit reporting bureaus, insurance companies, and law enforcement officials, but it will not be available to the general public.
FindUSA was very popular with genealogists looking for twentieth-century ancestors or for living relatives. It was especially useful for Jewish genealogy researchers trying to locate families dispersed by the Holocaust.
FindUSA was popular with libraries. A number of libraries subscribed to its rather expensive service. Generally speaking, it was better (cheaper) to use a library's subscription than to pay for your own.
The loss of FindUSA shouldn't be too big a concern. There are plenty of other companies offering similar services:
However, I would assume that all these companies are being pressured about privacy concerns. One has to wonder how long the others will remain in business if the best-known service has pulled out.