The real danger now is rarely eavesdropping — it is a fake network wearing a familiar name. Ask staff for the exact name, and do no banking on one you did not verify.
The drawing that proves the sentence above. It is the same card that is in the book.
Think of it as
a private conversation held in a crowded waiting room.
For example
The café has free internet. So does every person sitting in it, and you cannot see which of them is which.
This is one card out of 275.
The hundred words you meet most are free — the whole set, animated, in one file that works with no internet.
Volume 1 has all 275 in fifteen chapters, with Staying Safe the largest chapter on purpose.