On the other, the social fabric of social networks — precisely the element that makes them valuable to marketers — will deteriorate if we can't trust the people and numbers we see there.
This interesting urban element allows us to read some aspect of the morphology of the surrounding urban fabric and support an alternative public life than in the traditional street.
There are also loop invariants and a few others, but pre contract element condit- and post-conditions and class invariants are really the basic fabric of contracts.