President Barack H. Obama has allowed infringement upon the general populace's Fourth Amendment rights.
This has occurred through his allowance of warrantless obtainment of cell phone metadata from the company Verizon Wireless, amongst possible other companies, by the NSA.
Although not directly tapping conversations made, it still invades the privacy of millions by finding where any given call using the service of Verizon Wireless in the United States is reaching to at the precise time they did so, regardless of their innocent status.