defrost_

"Know Your Rights."
"Reporting Interface"
"Dashboard"

Inspiration:

Immigrant communities are currently being targeted by ICE agents. When people try to warn their neighbors about ICE checkpoints or raids, they usually do it in group chats or on social media. The problem? They dox themselves. They leave their phone numbers, profile pictures, and metadata visible for anyone to see.

We wanted to fix this mistake. We built DEFROST so you can be an active community protector without accidentally leaking your identity.

What it does:

DEFROST is a specialized, anonymous intelligence platform for tracking immigration enforcement activity.

Users can drop pins on ICE checkpoints or raids without creating an account or revealing their identity.

When a user uploads a photo of a patrol unit, our system automatically strips dangerous EXIF data (GPS, device model) before it ever hits the server.

Users receive a silent, geofenced alert if ICE activity is reported within 5 miles of their location, giving them critical time to react without needing to constantly check the app.

How we built it:

To protect vulnerable users from digital surveillance, we treated this as a cybersecurity challenge:

We built a custom compression engine in Swift that scrubs all identifying metadata from evidence photos. The location is verified by the app's internal logic, but the image file remains clean of GPS tags.

We used CoreLocation to calculate the distance between the user and the reported ICE activity locally on the device. This means the user's live location is never sent to our database so only the static location of the checkpoint is stored.

We utilized Firebase's anonymous login, ensuring that even if the database were compromised, there are no emails, phone numbers, or social profiles to leak.

Challenges we overcame:

We fought a critical regional configuration bug in the Firebase Console that blocked our storage bucket. We had to manually override Google Cloud settings to ensure our evidence locker was accessible for real-time image uploads.

Keeping a background listener active to detect ICE reports near the user (even when the phone is locked) required some extra battery-management optimization in iOS.