How about the many examples of people erroneously put on the TSA's No Fly list. That's a microscopically tiny database compared to what ObamaCare tries to implement and it's totally snafu'ed. There is near zero likelihood that the records held in the ObamaCare database will actually be yours and not (some mix) of someone else's. In the hospital for a broken leg? Come out with your liver removed because your med file got tagged with someone else's name. Complaint about that? Talk to the IRS.
DESIGNED to FAIL for SINGLE PAYER :(
Or the problems when millions of illegal immigrants using stolen IDs start having their data mixed with that of the real individuals - including medical history, blood type and billing.