As a Hebrew speaker, I wish the "shibboleth" idiom (which is a good one) was translated, rather than transliterated. laoned idioms are inherently exotic, and this one is worth demystifying
It means any choice of word (or pronunciation, in the literal example) that clearly identifies the speaker's group affiliations.
A good modern example is "LondonDerry/Derry. This'd be my my choice for an English translation of shibboleth.
These tweets are about hacking shibboleths, which is advanced mode. Basic mode would be just noticing shibboleths, and also why and how they so clearly identify speakers.
Shiboleths can have serious weight, can be used to disarm/arm. They're probably interesting to text analysis as a classifier. You can use them to reliably imply things about you, like patio does
One hack among many possibles. I'm looking forward to Mackenzie's modern Machiavelli YouTube series using Derries.