A quick primer on how keys and frames work in FC.  During sign up: 

1. User creates eth key on their phone.
2. Warpcast creates account key on its server. 
3. User approves account key onchain 

Eth keys can hold funds and can control your account. Account keys can only post messages from your account.

Technowatermelon. Elder Millenial. Building Farcaster. 

nf.td/varun

The eth key controls your account and is an Ethereum address.

The account key can post from your account, and is NOT an Ethereum address. 

This design is intentional and ensures that: 

1. users never have to give apps control of their account
2. apps never have to worry about users storing funds on keys they control

Enter frames. 

When you click a frame button, you sign a message from your account key. Or rather, Warpcast or Supercast sign it for you. 

A frame can never request a signature from your Eth key. If properly implemented, a frame can never touch an Ethereum address and your funds are safe.