The senior policeman says his officers, along with forces from across the United Kingdom, are prepared to deal with terrorist activity when the leaders of the world's eight richest countries meet at the Lough Erne Resort in June.
Taking part in an exclusive Twitter Q&A with The Impartial Reporter on the day a 60kg bomb was found in Fermanagh, Mr Finlay wouldn't be drawn on exactly who may be planning on causing disruption in the run-up to the event.
Billy_G (@Billy_G_80) asked if the PSNI believed there could be "a terror upsurge from IRA groups joint operating with others who dislike G8 countries?"
"We are aware of a range of groups who either jointly or individually might want to come together to cause some disruption," tweeted Mr Finlay, in response.
When asked if he thought the G8 Summit would "open the door" for an attack by dissident republicans, the officer replied: "Dissident republican activity is sadly an ongoing feature of Northern Ireland."
See Thursday's Impartial Reporter for full report and even more G8 news.