Various organizations saved some of them, but the groups could not keep up with the numbers.
Dr. Rabinovich said she hoped the groups could develop new strategies for taking on these hidden, overlooked scourges.
Analysts and diplomats, however, said they strongly doubted that the groups could operate in Syria, a police state, without the approval of the government.
Ms. Cleaver, for one, said she felt part of a special group because it was the first, and the groups could be quite different five years from now.
Many were convinced of their benefit by a small and inconclusive study published more than a decade ago indicating the groups could substantially prolong patients' lives.
Tracy Kay, the county's deputy parks commissioner, met with representatives from the community gardens and the museum in August to discuss ways the groups could work together.
Depending on how the legislation fares, the groups could eventually unleash a flurry of campaign literature directed at individual lawmakers, those told of the discussions said.
They also feared that Republicans might push through legislation stripping federal money from groups that provided free needles even if the groups could show that the money was being used for other purposes.
Commander Bob Broadhurst, who led the Met police operation, said the groups "could not have been more markedly different" from the TUC march, which was "overwhelmingly peaceful and good humoured".
Nottinghamshire police warned that the groups could expect to be arrested, like five women from Leeds and Manchester who were caught on the ground at the plant early on Monday morning when the alarm was sounded.
Some intelligence analysts worried, for instance, that identifying the groups could reveal that American spy services were eavesdropping on the militants — a fact most insurgents are already aware of.
