[nemomarx]

when you file your tax paperwork each year you have to tell them which bank account to send the refund to.

if someone else can file for you they can put in whatever info they like, so.

[ryandrake]

In a sane world, this would just be a case of fraud between the IRS and the fraudster, and the person whose information was used would have nothing to do with it. It's unfortunate that we have this need to call it "identity theft" in order to try to shift the responsibility to some unrelated third party.

[Mashimo]

But how do you authenticate when filling your taxes?

[nemomarx]

You give them your social security number, which is pretty easily leaked, basically.

if they think you're the target of identity theft they can step it up to requiring a PIN that they mail you?

[Mashimo]

Wow, that is .. quite some thing.

Here in Denmark we have MitID, which you kind of use for everything. Taxes, every private banking login (you switch banks, keep the login), signing documents, all kinds of healthcare websites and apps, student loans and what not.