I can add some information here as I used to work for a company and managed the "Little Old Ladies". My information is from 1995 when I changed jobs and I assume many courts have gone electronic but I would also be sure many have not.
Bankruptcy petitions were copied by the court staff and put on a public counter or table the next day for anyone to view...newspapers looking for companies that filed and people collecting for CRAs. Courts also had computerized indexes and PACER(Public Access to Court Electronic Records) that companies could dial into and download or copy information. Very easy to collect and verify.
Tax Liens were on Micrco Film or Books and reecorded chronologically so all you had to know was the date of the last visit. It was very easy to gather ALL liens/releases. More importantly, it is also very easy to VERIFY a lien or release.
Judgments were difficult depending on the court staff and how busy the court was. Most, but not all, courts restricted access so the collector had to request files, usually by case number and were limited to x files a day or x files pulled at a time. The problem was that you could look at hundreds of files and find only a few actual judgments. Looking for satisfactions was the same process but the return was much lower. AND, the collector had to keep going back over the same files looking for judgements and then the satisfactions. That is the main reason satisfactions will not appear without a fight or verification...they are just two few and far between to make it worth while for the collector to mess with...a lot of time spent with little return.