Sun Jun 5 22:20:02 EDT 2016

unique identifiers

It's (likely?) not possible to generate unique IDs without a central
authority.  One more reason to be fault-tolerant.

And an interesting illustration of how programming Erlang turns some
age old assumptions on its head.  Shared state is possible, but it
requires a process to handle its sequentiality, so stands out like a
sore thumb.