MIT’s network fell to a denial-of-service attack Sunday evening, allegedly by the Internet activist group Anonymous, cutting campus users off from Internet access to most websites for nearly three hours. The attack came in the wake of accusations that MIT’s role in the pending litigation against Internet activist Aaron Swartz contributed to his Friday suicide. On Monday afternoon, MIT spokeswoman Kimberly C. Allen confirmed that the outage was due to a denial-of-service attack (DoS).