[kragen]

> if any of the super answerers really wanted, they could have tried to sue for illegally making their answers available under a different license.

they can plausibly sue people other than stackoverflow if they attempt to reuse the answers under a different license. but i think it's very difficult to find a use that 4.0 permits that 3.0 doesn't

[StevenXC]

3.0 has a "bug" that makes it risky to use materials without very careful attribution:

https://doctorow.medium.com/a-bug-in-early-creative-commons-...

[miohtama]

I don't think this is a practical issue, really.

I assume linking to the original answer is sufficient attribution.

In the link you can find name, license and figure out if the answer was modified.

Also linking the answer in a source comment is the smallest professional courtesy everyone should be doing.

If you have some issue of not linking an answer then you likely do not deserve the answer in the first place.

[eviks]

The blog illustrates that such assumptions about what's a sufficient attribution are fraught with danger, so "the smallest professional courtesy" can expose you to a $150k risk