I think someone stole some of my items, as I can see with whom and shared inventory items?

[cain Warcliffe]

I have many years of having my account in secondlife, and have created many elements, and happened to look at my items on another site that they ought not to be and I need to know if anyone robbery access my account or the he shared without permission

[Madelaine McMasters]

Hi cain,

It is possible for people to rip textures and some geometry from in-world using "copybot" viewers. If you are sure that's been done to your creations, your only recourse is to file a DMCA (Digital Millenium Copyright Act) notification with Linden Lab.

Here's how to do that...

https://secondlife.com/corporate/dmca.php

Good luck!

[Lindal Kidd]

As Maddy says, the most usual method of "stealing" content in SL is with copybot software.  It can copy everything except scripts. It cannot copy things directly from your inventory.  The item has to be worn or rezzed in world. 

However, you mention the possibility that someone has gotten access to your account.  This can also be done, especially if you fall for a "phishing" scam that steals your password.  If you think that your account has been compromised, follow the advice at this link:  http://community.secondlife.com/t5/English-Knowledge-Base/Password-and-account-information/ta-p/700017#Section_.5 (What to do if your account has been compromised)