If you have hosted albums with Picasa, Google's Photo Hosting service, it's important to remember that if left public, your photographs will be indexed by Google, and will be searchable through Google's Image Search.
Picasa Web Albums have 3 "Visibility" levels:
- Public
- Unlisted
- Sign-in required to view
You should be careful to set the desired level for your album. You can read more about Picasa Web's Album Visibility here:
https://picasa.google.com/support/bin/answer.py?hl=en&answer=39551