I was shocked to read how recent this legislation is
"Under Ireland's 2009 Defamation Act, anyone "who publishes or utters blasphemous matter shall be guilty of an offence" and liable to a fine of up to €25,000 (£21,200)." Independent newspaper, link given by Freddy Headly

It does look like someone reported Fry's speech in order to draw attention to how the law could possibly be (mis)used:

" 'I told the Garda I wanted to report Fry for uttering blasphemy and RTE for publishing/broadcasting it and that I believed these were criminal offenses under the Defamation Act 2009,' the person told the news site. 'I simply believed that the comments made by Fry on RTE were criminal blasphemy and that I was doing my civic duty by reporting a crime.'

"Local authorities told the Independent that they are investigating the complaint but that charges are unlikely." Huffington Post
http://www.huffingtonpost.com/entry/stephen-fry-faces-blasphemy-probe_us_590f1ad4e4b0e7021e984f5a