Boston-based Partners HealthCare System notified 3,300 patients that hackers got access to employee emails that contained Social Security numbers, health insurance information, and medical data. Partners should have known better than to allow employees to send sensitive patient data via email, experts said. The number of data breaches reported by healthcare companies rose 60 percent in 2014, according to PricewaterhouseCoopers. Partners said it is stepping up employee training about phishing and enhancing “existing technical safeguards” to protect patient information.”]