The first thing you do when you enter an online chat room is conceal your identity. You use a chat nickname, not your real name. Is that lying?
It is not a lie because for safety reasons kids (and adults too) should not give out any information that could identify you to strangers. Online - everyone is a stranger.
Does it stop there?
Where do you draw the line on lying online? A common practise in most chat rooms is a request for "stats". You are being asked for your - age/gender/location.
While age and gender can be harmless to give out in most instances giving out your location is not appropriate. You should be as vague as possible - only giving out country - or province/state. Never give out specific town/city information or specific home addresses. Is this lying?
Again, for safety reasons you should never give out your location to strangers online. This tiny bit of information, that can seem harmless enables strangers to track you.
Does it stop here?
You should always protect yourself online when it comes to personal information - anything that makes you feel uncomfortable answering does NOT have to be answered. This is not lying.
For some though, the anonymity of the Internet (hiding behind a nickname) allows you to make up just about any lie you want. How will anyone know if you are telling the truth?
You could be anyone one you want, you could be rich or poor, know famous people or have an uncle who is a race car driver, you could be the smartest kid in your class, or you could be suffering from a terrible disease. You could create some pretty "out there" stories about yourself - and who would be the wiser? Is that lying?
In my opinion,
Living lies, even online, can be a pretty big burden. You need to remember who you told what to and the details of your lie - and as you tell it will grow and grow until soon you won't know the truth from lies. Covering up these lies and creating bigger ones to cover up those ones, is an awful lot of work. Soon, you will be hiding from people because you can't remember your own lies.
Sooner or later you will be caught in your web of lies. You will trip up and someone will question you. This can be both embarrassing and humbling. Is it worth it?