One thing you will need to remember when you are at an online casino is the fact that it is not yours to run and be in charge of. You are paying to be a member of the club 
and in that instance then you will need to make sure you are following the guidelines that they have set forth in order for you to be a member. This means you will need to know what it is you are going to do and how it is you will be allowed to play at the virtual casino. Know what is acceptable behavior and know what it is that the casino would consider unethical.
If you are aware of these and other rules you agreed to upon becoming a member then you will be able to have a fun and happy time while you are there. If you ignore what they dictate then do not plan to be there for very long. Most of the rules are pretty much common sense, and if you are a regular at a casino of any sort you will be familiar with most of them. But you should definitely have a look through the rules for each online casino site, as some of them will be unique to each casino.
Of course, being a virtual casino, you will be able to do certain things that you cannot do in a regular casino. For example, in many regular casinos you are not allowed to smoke at some tables. Of course, if you are playing on your computer in your home then you can smoke whenever you want. Also, you will not be able to bet over the table maximum when playing online. If the maximum was $100, then you would not be able to bet anything over this amount, the system will not let you. So in circumstances such as this there is no way that you can break the rules.
Some online casinos will have some multi-player games available. This is where you can play one game with several online players at the same time. Some of these multi games also have a chat box so you can interact with them. In these cases you need to make sure you are always civil with them and not abusive at all. This is one way you can get in trouble with the online casino.