[beat]

If someone is working for free on a voluntary basis, they're probably not being "exploited". When I was trying to build a startup, I got plenty of free help from various friends and interested parties who were excited about what I was building - but nothing on the level of employee-level work. Hell, if someone was remotely useful and willing to put in real hours, I'd have called them co-founders and given them equity, happily.

This is important! If someone has enough skills/ambition to be actually useful to an early stage startup, they can make better money elsewhere. So if they're putting in their time with the startup, they're being motivated by something else. That doesn't mean they're being exploited. It means their interests can't be measured entirely in dollars.

[joshuakarjala]

Plenty of startups have students / recent grads in marketing, pa roles working 20-40 hours a week for no pay.

[beat]

Are they getting equity? Experience? Networking? Fun?

As long as they feel like they're getting something useful from the experience, then I don't think "exploited" is the right word. And if they think they're not getting anything out of it, it begs the question just how that early stage startup is going to make them stick around. Exploitation involves more stick, less carrot.