In today's terrorist and crime environment it is justified for Obama to be using a certain amount of spying techniques to ensure our safety as a country. This can be controversial as many people do not like to be spied on at all. However, our safety is more important as a country.
No, the Fourth Amendment of the Constitution protects citizens from unlawful search and seizure. The NSA claims that what they collect is meta-data, times and durations of phone calls. However, even this is a violation of the rights guaranteed in the Constitution. The ability to know exactly when a person made a phone call constitutes knowledge that is gained unlawfully.