: Traditional publishers moved online with sites like Whitepages.com and Yellowpages.com.
Before the mobile era, telephone directories were a household staple: cell phone directory
: Mobile users expected their numbers to be private, viewing their cell phones as personal devices rather than public utilities. : Traditional publishers moved online with sites like
: Today, the "directory" has been replaced by search engines and specialized apps like Truecaller or NumLookup, which use proprietary algorithms and public data to identify unknown callers. cell phone directory
: In 2004, Congress passed an amendment to the Communications Act of 1934 to prevent a national mobile phone book.
: Directories eventually split into residential "White Pages" (listed alphabetically) and business "Yellow Pages" (listed by category).