Is it a joke?
1984 is now...inform on your neighbor...like a good citizen.
Pros:
1. Sounds like a gold rush for them if the proposed law is effectively enforced.
2. Likewise for the businesses and unions for subcontractors and suppliers (of construction materials).
3. Dramatic expansion of jobs in the human warehousing sector.
4. Substantial increase in illicit drug prices to reflect the opportunity cost as modified by this proposal.
5. Bonanza for lawyers, judges and court employees as well as correctional officials.
6. Interim good luck for homicidal sexual abusers of children since there will be so little prison room for them in the meantime while we await the creation of the new prisons.
CONS:
1. America and Americans go absolutely broke providing for 10 million or more new prisoners in the neverending crusade to worry ourselves to death over marijuana. (Mind you, I am no fan of mary jane or other free market pharmaceuticals, but I can think of more important expenditures like expanding the armed forces' regular enlistee numbers, acquisition and repair of weaponry, etc., even debt reduction).
Feel free to add more cons. For me, my #1 con is sufficient.