www.withersworldwide.com/news-publications/irs-says-you-owe-us-money-%E2%80%93-bye-bye-us-passport
www.bipc.com/updates-on-denial-or-revocation-of-passport-in-case-of-certain-tax-delinquencies
www.withersworldwide.com/en-gb/no-us-passports-for-us-tax-cheats
Update:
www.bakermckenzie.com/en/insight/publications/2019/07/irs-and-state-department-set-to-issue
www.irsstreamlinedprocedures.com/irs-passport-revocation/
www.plunkettcooney.com/dontbetthebusinessblog/IRS-passport-program#page=1