(much more recently, there has been some controversy about the publication of a way of obtaining a particularily infectious strain of a certain virus, but I can't find any references for that right now)

This is a perennial issue, occurring in various forms relating to the preservation of viruses like smallpox, the sequencing of their genomes, and increasing their virulence. Looking in Google News for 'virus research increase virulence', it seems the most recent such research would be http://www.nature.com/news/biosafety-in-the-balance-1.15447 / http://www.independent.co.uk/news/science/american-scientists-controversially-recreate-deadly-spanish-flu-virus-9529707.html :

Groups led by Ron Fouchier of the Erasmus Medical Center in Rotterdam, the Netherlands, and Yoshihiro Kawaoka of the University of Wisconsin–Madison created a storm in late 2011 when they artificially engineered potentially pandemic forms of the H5N1 avian flu virus. In January last year, researchers ended a voluntary 12-month moratorium on such gain-of-function flu research, which can increase the host range, transmissibility or virulence of viruses (see Nature 493, 460; 2013), and work resumed.

This month, Kawaoka’s group reported that it had engineered a de novo flu virus from wild-avian-flu-strain genes that coded for proteins similar to those in the 1918 pandemic virus (T. Watanabe Cell Host Microbe 15, 692–705; 2014). The researchers were able to make a virulent version that could transmit between ferrets, and they concluded that a 1918-like virus could therefore emerge from wild avian flu viruses.

EDIT: Sandberg provides an amazing quote on the topic: http://www.aleph.se/andart/archives/2014/07/if_nature_doesnt_do_containment_why_should_i.html

Although fellow flu researcher professor Wendy Barclay at Imperial College said there was nothing wrong with doing the research in a BSL-2 lab: “In nature there is no containment. He’s only doing what happens in nature every day.” Which is true for ebola too.