I want to know if a photo published on the Internet can be traced back to its original poster?

Depends really, but I would be tending to say NO.
However dont post a pic of yourself or anyone you know because someone who knows you might also be a member.

If you right click on a picture and select properties you will see the where the picture is being loaded from, if from another website it will show the address of that site (try it on your avatar, then on mine which I upoaded), if the picture was uploaded from a PC then you will see "http://cannabis.community.forums.ozstoners.com/uploads/" with a file number stuck on the end as you have uploaded (copied) the file onto the Oz Stoners server and it is opened from there, not your PC.

thanks guys

yes it can. anything you write, post, even visit on the internet can be traced back to you. The probability of anyone with the skills to do this bothering to do it are extremely small however.

thanks auto..i guess that answers my question

There are a few ways to better protect your identity, just easy, generic stuff, but worth noting nonetheless:

WHERE you upload to:
Where you upload the picture is important [where the picture is located and stored on the internet... it could be 'uploaded' to these forums, it could be stored on your webspace, or it could be slapped on one of those free image hosters..]. If the place where it is hosted is associated in any way with you, then there's a risk there. Uploading to ozforums is fine, uploading to the random image hosters [for e.g. imageshack.us] is fine, but don't upload bad stuff to your personal or business or otherwise you-related hosting.

HOW you upload:
Whenever you upload something, be sure to use working and anonymous proxies [read up on these if you're not sure what/how]. These are a lot harder to trace, especially if you chain them, but really it's a case of if what you did justifies the effort needed on the pursuing end of any investigation to find out the original author [you] of the issue.

WHAT you upload:
Technical ideas aside [I doubt you would somehow manage to accidentally brand the image's properties with your details, or slap your name into the image description or properties], be careful of what's in the picture itself. Check all over thoroughly - it may have some personal details that the photo angle may have caught, or some strange fauna [not weed ] found only in certain areas, or other noticeable geographical features.. Just anything that could identify you if somebody recognised stuff in the picture.

Good luck, and don't forget to read up on it if you're worried. I guess it's really a case of, the bigger the risk, the more security needed.

So thats why the Minister wont take my calls

comming from the gate keeper himself we don't keep upload logs they are the property of Ozstoners and anyone who accsesses them does so from our servers if you host it somewhere else we can't help you protect your images though , as for what can be traced back to you all I take pretty good care of you but I still reccomend peopel use proxy servers ect , adn just not be stupid with what you do
remember never to accsess anythign important on a proxy though like netbank or making a credit card purchase as there is a potential for the person running the proxy server to keep your information for as long as they wish , it happens a fair bit too so just be wary