The Unformatted SSN features can only be modified in Enterprise Edition.
If enabled, the Only Match Unformatted SSNs When Location Contains Keyword setting will require Identity Finder to also locate a keyword (i.e., SSN, Social Security Number, SS#, etc.) anywhere within the result location. This option is enabled by default and helps to eliminate many false positives.
To view or change these settings, click the Settings button on the Tools and Options ribbon.