The authorities are now looking for anything that might have been part of the explosive devices - bits of metal or sharp objects that they might be able to traceback to its owner or owners.
He thinks the financial services industry should create the identifier at the time of origination rather than work with closing and settlement records and then relying on data vendors such as Bloomberg or Reuters to traceback the instruments.
"I've got lots of examples from research where college students and older say, 'I feel uncomfortable in a certain situation, and I trace it back to news or movie, ' " she said.