On October 7 this year, a letter landed with Sarah Cremin, clerk of the Oireachtas Public Accounts Committee, from Fiach Mac Conghail, chief executive of the Digital Hub Development Agency (DHDA). In the two-pager, Mac Conghail gave a brief breakdown of vacant site levy costs incurred by the non-commercial agency, requested by the committee after examining its 2024 accounts.  The hub, opened in the heart of the Liberties in the early 2000s to develop Ireland’s digital enterprise sector, is today home to the offices of a cluster of tech and digital media companies.  This includes the likes of the news…