The National Security Agency's Internet surveillance has been more widespread than officials have publicly said.
The Wall Street Journal reports the NSA has built a surveillance network that can reach roughly 75 percent of all Internet traffic.
The network is designed mainly to look for international communications, but it also collects domestic conversations and emails.
Officials say the NSA isn't just going through online discussions but rather looking for "important" information.
Still, some lawmakers and civil libertarians worry that the agency doesn't have enough safeguards to protect Americans' privacy.