what is an eruv and what does fishing wire have to do with it?
oh, and what is fishing wire?
It’s related to a rule from the Talmud that if they take a bit of string they can fence off an area outside their home and then they can use that area on the sabbath as if it were inside their home. Harmless enough, but if you decide to extend that to stringing off whole neighborhoods, I think you are ignoring the spirit of the rule.