Google Sidewiki entry by Russell

For me, the obvious question is why the eruv needs to consist of “a network of poles and strings”? Why not simply paint the boundary lines on the pavement (with the assistance of the local council, of course)? Oh, that’s right, I forgot, Moses himself set out the manner in which an eruv must be delimited. He didn’t write it down, of course, but a handful of later sages managed to interpret what he didn’t say...

in reference to:

"The eruv, which usually consists of a network of poles and strings, defines an area within which religious Jews are allowed to carry items outside their homes on Shabbat. From the standpoint of Jewish law, it essentially makes this area "private" rather than "public.""
- Rift has roots in eruv dispute - Haaretz - Israel News (view on Google Sidewiki)