Remember that EVERYTHING you DO online is RECORDED in a SERVER somewhere.
If you make a MISJUDGEMENT and "ACCIDENTALLY" write things you shouldn't or post images that you shouldn't or move or copy or in any way change someone's files without their express permission eventually you CAN be held accountable.
IP addresses CAN be traced and WILL be traced if the MISTAKE is OFFENSIVE to someone.
If it is offensive enough, it could tarnish your reputation for life and cost you future career opportunities.

Since entering into cyberspace is such a SERIOUS venture it is essential to study and learn the Internet Safety and the netiquette rules as suggested below as excerpted from the book Netiquette by Virginia Shea and in the following links as edited from the Mann Middle School website
Rule 1: Remember the Human
Rule 2: Adhere to the same standards of behavior online that you follow in real life
Rule 3: Know where you are in cyberspace
Rule 4: Respect other people's time and bandwidth
Rule 5: Make yourself look good online
Rule 6: Share expert knowledge
Rule 7: Help keep flame wars under control
Rule 8: Respect other people's privacy
Rule 9: Don't abuse your power
Rule 10: Be forgiving of other people's mistakes