Age Verifications: where do you draw the line?

choose all that applies

boosts appreciated 

against with the idea in principle (no other options applies)
34.8%
a self-certifying checkbox is okay
47.9%
offline verification of ID document is okay (via reading chip or OCR)
7.2%
Credit card verification is okay (if you have one you are >18)
5.9%
Mobile operator verification is okay (if you have a contract you are >18)
2.7%
First party online verification is okay (upload ID or photo to the website you are using)
0.4%
Third party online verification is okay (upload ID or photo to another website)
0.2%
other (write in)
1%
Poll ended at .
@kuriko If Age Verification has to exist, these are the only forms I will tolerate:
-Self-Certifying Checkbox
-Offline Verification of ID Documents
-Credit Card Verification (should be expanded to Debit Cards as well, Banks know your age)
-Device-Based Verification (i.e. apps and sites only know a user's general age category)
-Zero-Knowledge Verification

Again, I'm not saying these are good, rather they are the least bad. Online scans of ID documents (Government ID, Passport, etc.) are a privacy and security nightmare.