They havn't been stolen.... you gave them away. Remember that "Click here to agree to these terms and conditions" button that you clicked "I agree" on when you signed up????
6. Proprietary Rights in Content on Photobucket.
o 6.1 Photobucket does not claim any ownership rights in the text, files, images, photos, video, sounds, musical works, works of authorship, applications, or any other materials (collectively, "Content") that you post on or through the Photobucket Services. By displaying or publishing ("posting") any Content on or through the Photobucket Services, you hereby grant to Photobucket and other users a non-exclusive, fully paid and royalty-free, worldwide, limited license to use, modify, delete from, add to, publicly perform, publicly display, reproduce and translate such Content, including without limitation distributing part or all of the Site in any media formats through any media channels, except Content marked "private" will not be distributed outside the Photobucket Services. Photobucket and/or other Users may copy, print or display publicly available Content outside of the Photobucket Services, including without limitation, via the Site or third party websites or applications (for example, services allowing Users to order prints of Content or t-shirts and similar items containing Content).
In other words.... by putting your photos on photobucket, you grant anyone who can find them the right to use them