Two hundred Catholic priests and 500 nuns in their vestments, together with civic groups, protested at Seoul Plaza on September 23, 2013. A total of 5,000 participated in the demonstration which took the form of Mass (police estimate below 2,000), and it is the first time  [ko] in recent decades that the Catholic Church as a group has organized a large-scale demonstration.
Back in mid-August, a little over 4,500 clergy members gathered at Sogang University, the alma mater of the current President Park Geun-hye, to release a manifesto that calls on the president to investigate and apologize for the spy agency scandal. Prominent citizen journalist Media Mongu posted a YouTube video  of the scene.
A Catholic priest (@ngo7979) and Nun Juliana (@nun1004) tweeted photos of the protest with comments, as seen below:
더 이상 민주주의 훼손을 지켜볼 수가 없습니다. 오늘 “국정원 해체와 민주주의 회복을 위한 미사”에 첨석하신 모든 분께 고마움의 인사를 전하며 민주주의 회복을 위해 끝까지 함께해주세요~ pic.twitter.com/7Zful0Bm9s 
— 세월의 더께 (@ngo7979) September 23, 2013 
We can no longer stand idly by while our democracy is being harmed. I want to say thank you to all of those who participated in today's Mass calling for the National Intelligence Service (NIS) to disband and for the restoration of our democracy. Please stay with us till the end.
상식과 보편된 진리가 통하는 날까지…함께합니다… pic.twitter.com/0WddO9Zpn9 
— 율리아나 수녀 (@nun1004) September 23, 2013 
We will stand together till truth and common sense prevail.
광장의 신부님들. pic.twitter.com/OMlejU2rVs 
— 하늘걷기 (@actwalk) September 23, 2013 
We see Catholic priests at the Plaza.
300여명의 사제단 입장-서울시청관장 시국미사 pic.twitter.com/ITQfkKX6xq 
— 하늘정원 (@bonghaaa) September 23, 2013 
This is the scene of 300 clergy members entering the demonstration place during the Mass at the Seoul City Hall Plaza.
One of the nation's beloved bestselling authors, Gong Ji-young, tweeted a photo  of the rally and wrote a commentary  [ko] about the long history of the Catholic Church functioning as a refuge for democracy. For instance, back in 1970s and 80s when two dictatorial regimes ruled the country, Myeong Dong Cathedral  in the heart of Seoul became an iconic bulwark of the democratic movement by hiding and defending activists.
카메라가 눈의 감동읗 다 전하지 못하네요 pic.twitter.com/nNU98vpHyN 
— 공지영 (@congjee) September 23, 2013 
The emotion cannot fully be delivered through the camera lenses.
@congjee : 박종철 고문치사 사건도 신부님이 폭로하신. 한장의 쪽지로 시작되어 6월항쟁의 도화선이 되었죠 RT @tgs432004: <속보>천주교 사제단 시국선언문 중에 “사전에 개표결과가 조작되었다는 의혹이 있다” 처음으로 천주교 시국선언에서 투표조작을 거론합니다[…]
@congjee : Park Jong-chul's torture and death  is also a case disclosed by a Catholic priest. A memo by him [reporting Park's death] sparked the June Democracy Movement  [in 1987] RT @tgs432004: <breaking news> Catholic clergy's statement contains a clause that ‘there is a suspicion that the [presidential election] voting tally has been manipulated even before [people cast votes]’. It is the first time the Catholic Church has brought up this election manipulation issue.
Protests against the NIS scandal have continued for over four months now, and religious groups who usually remain silent have joined  one by one – starting with the Catholic Church, several factions of Protestant Church, and Won Buddhists. Net users have tweeted comments on why religious groups are taking action. One tweet read:
2. “천주교가 나설 수밖에 없는 것은 정당과 사법부 등 국정원 사태 해결을 책임져야 할 주체들이 제구실을 못하고 있기 때문이 아니겠냐”고 말했다. -천주교인권위원회 이사장인 김형태 변호사
— creation (@bonaventura0) September 23, 2013 
The reason why Catholics had to take a stance is because neither of the major players, such as the political parties and the Ministry of Law, who are supposed to take the responsibility for this NIS situation, have functioned. – The Board of Directors of the Catholic Human Rights Committee, Lawyer Kim Hyung-tae