How are ERC20 tokens transferred? 1. transfer 2. approve and transferFrom Giving unlimited approvals is risky. Unicats scam: https://decrypt.co/43927/ethereum-user-scammed-for-140000-in-uniswap-uni-tokens Bancor: https://cointelegraph.com/news/bancors-bug-exposes-dangerously-common-practice-in-ethereum-defi