This document summarizes a presentation on grid security given at an Atlas Tier 2 meeting. It discusses the rapidly changing security environment with new federal guidelines, threats from attacks and vulnerabilities in middleware and applications. Recent security events from the past weeks are noted. The presentation emphasizes designing security into systems from the beginning through practices like mutual authentication, logging, and patching. Examples from SLAC's Atlas experience and a proposed updated user agreement policy are provided. The Open Science Grid security team and plans for security auditing, dynamic firewall ports, identity management and securing middleware are briefly outlined.