Well, this is a tad disturbing.

How Easy is it to Get Tax Information from the IRS? Very.
The IRS has earned its reputation through complete and utter indifference to the plight of its customers: the taxpayer. I wanted to see if this indifference extended into the way the IRS handles taxpayer data. So, I decided to do a little investigation and see just how easy it would be to call and get someone at the IRS to fax me my life. What I found out shocked me and it should shock you, as well.

To get the info, all you need is a name, social security number, date of birth and mailing address. Oh yes, they do ask you if you are the named taxpayer. You have to say yes. Tough security, huh? Perhaps the most entertaining aspect of this entire thing was the fact that on the cover sheet, the IRS tells anyone who may have gotten the communication in error to mail it back to them using the US Postal Service. They then failed to include an address at the bottom of the fax.