According to information received from Google the company is developing an application which will be able to recognize people. 

So due to this program it will not be hard to find out the telephone number of the person you like or on the contrary do not like  in case you have the  picture of this person.
It will be very easy to identify people soon. The photo is in connection with other pictures of the person and those pictures might be connected to your personal data. Though the news sounds threatening users are urged not to worry and do not think about the privacy violation rights. The company guarantees that this will not be used against people.

The feature will be provided with a check box that will many times repeat the same questions in case somebody requires the access to your personal information.
According to the reports Google has similar scheme of work with functions resembling Google Goggles. This service enable the customers to get the information about the product when they have its photo. The company also announced social-search tool with the same mechanism in the basis. Still many people are not so happy about the development of technologies in this direction as this is threatening their privacy not only online, but in real life as well.