Volunteering at Beer festivals ?

Beer festivals tend to be commercially backed and tend to use casual paid staff NOT volunteers so no wonder she was turned back.

What was the point in the volunteer story ? I'm visiting friends for the summer would likely have not raised as much as an eyebrow as it's a common thing for students to do.

As for the rest of your rant - Don't be so daft -If I rocked up to US immigration with the same story I'd not be admitted either (I'm a female UK citizen)

Conspiracy my backside - SciFi cons are considered a "hobby" activity (yes I know there's money to be made from SciFi-I'm talking perceptions)- breweries are a business -so she shot herself in the foot.