At times, search engines remove different results from different country-specific searches in response to requests originating under differing local laws.
This page offers a side-by-side comparison of Google searches in different domains. (Google also appears to weight its algorithms differently in searches from different domains, so absence of a result from one screen does not necessarily mean it has been removed from the index.) This tool is derived from the OpenNet Initiative's Google China comparison.
Enter any search term into the box below and see for yourself.