In all seriousness, with regard to taxes, there is a very simple thing to do — ask them to send the request in writing.
Seriously, I don’t think the IRS *ever* initiates contact with people except via mail — and I would be surprised if the state did so as well.
So, if someone calls from a 202 area code (Washington DC) and says that they’re from the IRS and they need to confirm some details, ask them to send you the request in writing.
As a general rule, never disclose sensitive information to anyone unless you initiated the call.
The Wolf