Read the following article and select the best answer. Article: It was reported last week that developers could take photos from Apple mobile and Google Android devices without the phone owners knowing that the images were being taken. In Apple's case, developers can also obtain the location information for each photo. Senator Charles Schumer said in a telephone interview that his office had spoken with officials at both Apple and Google on Monday. "We asked them if they could find a way on their own to prevent Apple from having access to private information," Mr. Schumer said. "They were friendly and open to the idea that this ought to be changed." On Sunday, Mr. Schumer said that he planned to send a letter to the Federal Trade Commission asking the agency to investigate Apple and Google after the privacy concerns came to light. Claudia Bourne Farrell, an F.T.C. spokeswoman, said the agency had received the letter but she could not comment further. "It worries people to think that one's personal photos, address book, and who knows what else can be obtained and even posted online without permission," Mr. Schumer wrote in his letter to the F.T.C. "If the technology exists to open the door to this kind of privacy invasion , then surely technology exists to close it, and that's exactly what must happen." Mr. Schumer said if Apple and Google could not come to an agreement to fix the problem, then he would be forced to take the issue further. He said other companies had been willing to work with his office to fix issues. "I'm optimistic that we can get this changed without any regulation," he said. "If it's not changed, then we'll turn to the F.T.C., and if that doesn't work then we'llconsider legislative approach." The F.T.C. has warned companies to try to be more vigilant in their efforts to protect consumers when it comes to privacy. Question: Mr. Schumer's letter to the F.T.C. mainly shows that the technology to open the door to privacy invasion _ - causes privacy invasion to happen frequently. - can be used if permitted. - causes personal information to be posted online without permission. - causes people to worry about the safety of their personal information .
A:
causes people to worry about the safety of their personal information .