The Chief Executive of Tusla has said that the online harassment faced by frontline staff poses a real-life threat to their safety and privacy, and could hinder the agency's ability to retain social workers.

Bernard Gloster said that he and many others in Tusla have been targeted over social media in recent months, with a campaign run under a hashtag on social media sites that named him and his address online.

He said he has had three or four weeks of close contact with An Garda Síochána as a result of "very live and visible messages" online with an anti-Tusla element asking people to come to his home.

One video showed a campaign organiser thanking people for providing Mr Gloster's home address.

He said: "There is a sense of constant waiting and watching of videos to see who is next".

Mr Gloster raised his concerns with Twitter directly and asked them to remove the hashtag and associated videos "as in our view it does not represent freedom of speech ... but in my interpretation is targeted harassment".

He said he was disappointed with the response in which Twitter confirmed it would not remove the content in the interests of freedom of speech and the public interest.

Mr Gloster said he has no difficulty with peaceful and lawful protests where people want to raise issues with Tusla, but said: "I do think it crosses a line in relation to personal safety and concern when they say they are going to bring your work to your home".

He is not prepared to accept that for himself or his 5,000 staff, he added.

He said there is a "real, live danger and threat of it coming to their homes ... and this would make it impossible to find people to do the work".

Mr Gloster said that over the last two years there have been issues of harassment of Tusla social workers online, where staff have been followed and their car registrations have been filmed.

There has been discussion about staff members' private lives and children online, and in one instance there was a concerted effort to find where one senior staff member was celebrating Christmas with their family, he said.

Mr Gloster said that there are external and internal mechanisms for people to lodge their complaints with Tusla but this goes beyond that.

Tusla continues to make representations to social media companies in relation to individual messages online and hashtags that refer to staff of the agency, he added.