If you ever “need” to do free work for an interview that involves coding or access to external links, include autodestructing code or links that you can break afterwards.

For instance, an excel worksheet with formulas;

if(and(day(today())<25;month(today())=5); [formula that works];"You can call me back at the 514-555-1234")

Comes May 26th, kaput. Password protected, and you could even add a few layers of fuck you by making the formula very convoluted and hard to work with just in case they're a little savvy.