Install latest Nimbuzz 1.1 or 1.2 on your Pc
1. First select option show offline contacts
2. Send add request to the person u want to steal profile pic
3. U'l see that person offline in list ,Immediate Open hes/her profile.Now click on hes display pic for zoom.
4. Right click on zoomed pic. You'l see options save,copy on clipboard,set as your pic