Yes. The Infinity Wall consists of user generated content. The purpose of the Infinity Wall is to not only share your work with others, but to allow others to use your creations in their designs. It isn't uncommon for users to use designs from other content they have found. Be proud that your content has inspired another builder to build off of your designs! If you do not like the idea of others using your designs, It is suggested that you do not upload your content to the Infinity Wall.
Note: If someone tries to copy your content to add it onto the infinity wall as their own creation, the content will still credit the original creator.