SheepylolOnd_kaja
1. Don't use IRC without protection (VERY important):
When you join a channel in most IRC servers, your IP can be grabbed with minimal effort. How to protect yourself differs from server to server, use google. A bouncer is the best protection.
2. Don't accept random skype/steam calls. Steam/skype voice calls are P2P so they can get your IP from this.
3. Don't click fishy links. Could be an IP grabber.
Just a little bit of common sense will protect you from most vulnerabilities, having to do further than basic efforts scares away most script kiddies.
For preventing server ddoses:
1. Go offline on steam (otherwise the IP will be shown in "view game info") BEFORE joining a server.
2. Don't use serveme.tf servers. They are great, but they are also not protected.
3. Server cvar "hide_server 1" so it doesn't show up in the server browser.
The RheinBrigade servers and all French ones on serveme.tf are DDoS protected. The issues we're having at the moment is the type of attacks aren't being mitigated on these servers.