U.S. law enforcement agencies have disrupted more than 50 terrorist plots with the help of controversial surveillance efforts, officials say. Officials with the NSA and the Department of Justice defended the surveillance programs during Tuesday’s hearing. Officials contradicted allegations by NSA contractor Edward Snowden, who has said the few controls at the NSA are easily circumvented by NSA analysts. Officials say the surveillance court is not a “rubber stamp” for the NSA as some critics have suggested, officials said. Some lawmakers say they are uncomfortable that the NSA is collecting massive amounts of phone records.”]