The website of pro-life group Youth Defence has been attacked and replaced by an image promoting a yes vote in the marriage equality referendum.
Visitors to youthdefence.ie this morning were greeted with a single image of the mural on Dublin's George's Street by artist Joe Caslin, showing two men embracing.
The title of the site displayed in the browser's window bar or tab was also changed to read "VOTE YES".
The site's source code was replaced with a simple segment of code setting the background to the mural and the changing the title, with no further message or information.
Links to known pages on the site return server errors, suggesting the content was deleted from the group's servers.
Youth Defence describes itself as "Ireland's largest and most active pro-life group", and has campaigned against measures legalising abortion, including the recent Protection of Life during Pregnancy Act.