Protesters brandish placards while businessmen scurry into a heavily guarded building - it's a classic image from world trade meetings but it's not the whole story and a little out of date.
Today, some of the non-governmental organisations (NGOs) whose activists once protested outside such gatherings are spreading their messageinside, having been brought into the process because of their rising influence as campaigners for the world's least developed nations.
When the World Trade Organisation (WTO) holds what may be make-or-break talks in Hong Kong from December 13, the relationship between politicians and NGOs will again be tested.
Some on both sides say the relationship has improved dramatically but others warn that tensions remain.
"NGOs do have a growing influence but I'm not convinced it is perceived as a positive force by some decision-makers as they are still blamed in some circles for the collapse of the WTO Cancun meeting [in Mexico] in 2003," said Aldo Caliari, of the Washington-based development group Centre of Concern.
NGOs represent a huge range of interests and despite some NGOs' inclusion in the political mainstream, others are still treated with suspicion by Governments and corporate interests.
Even NGOs recognise that things can still turn nasty.
"I hope Hong Kong will be friendly and constructive," said Gawain Kripke, senior policy adviser for Oxfam in Washington. "A lot of critics have strong feelings about the way these negotiations are progressing and they want to be heard. If there's no other way for them to articulate their point of view then violence can be the result."
The Hong Kong meeting was originally meant to cap four years of hard bargaining with a deal on a blueprint for a new treaty on slashing rich nation subsidies and opening world markets.
The painfully slow progress on farm subsidies has already drawn stinging comment from NGOs and prompted attacks from poorer countries, who want better access to rich nation markets.
Previous WTO ministerials have been incendiary. In Seattle in 1999, protesters battled police, leading UK's then International Development Minister, Clare Short, to denounce the rioters' "misplaced criticism".
