These disks cannot be read by CD-ROM drives built before 1997. CD-Rs containing back issues of the newsletter of my Capt. Daniel Little Family as PDF files to be read by the free Adobe Acrobat Reader . Then the newsletter issues are preserved for the long term. I also use it to send large genealogy files to others.
Some people are very concerned about privacy with regard to genealogy data.
They do not seem to realize that dates and places of births, marriages and deaths are public records. So one could always collect from the public records and be perfectly correct in making those data available to anyone. However, much genealogy data comes from the memory of persons and perhaps this makes some people think that those data for persons still alive should not be made public. Some genealogist delete all dates and places for people who are thought to be living. There are programs for doing this automatically for gedcom files.