URL issues

The issue is basically about URL redirection access problem...Here is the description that how this issues arrive in my project...

I have created 10 role in taxonomy...i can entered data with selecting of any one role....

Each role has several users...

Now when i logged in as one of the user then also i can access different user data by writing their node in URL...

like : http://mydomain/node/12345(node id of different role)/edit

Using this type of URL i can access any node of different user....

So the issue is : How can i prevent this URL redirection by role wise...

Thank You in Advance.....

_{edited by silverwing- changed forum}