Vacuuming
Vacuuming is when state and quasi-state actors work to neutralize and disorganize the left by pushing forward a flashy and exciting organizer or organization and encouraging all other organizations to fall in behind or fold themselves into the vacuuming project. The vacuuming project can be given preferential media treatment, be allowed to break the law in ways other activists would not be, and can involve paid professionals, in contrast to most leftists who are stuck with day jobs.
Often, respected members of the activist community will enthusiastically promote the new project. This promotion may come from people seemingly ideologically very distant from each other, so that the vacuuming project appears to be the one thing everyone agrees on.
These carrots are sometimes combined with a stick, i.e. some kind of attack on groups and individuals that remain aloof from the project.
The vacuuming project is typically everything to everyone: It is anarchist if you are an anarchist, Trotskyist if you are a Trotskyist. If you're just a progressive Democrat? Go Bernie.
Generally it actually has little or no meaningful ideology. As a result, participation in it tends to result only in burn out for honest activists — which, after all, is the point.
Vacuuming on a grand scale is a well-known tactic. One example is Father Gapon, a Tsarist secret service agent who was assigned to create a fake workers movement in pre-revolutionary Russia. His movement was allowed to organize freely, of course. Another would be the Spanish Socialist Workers Party, which was allowed to organize and even given state help to organize in fascist Spain, with the result that once fascism fell, the Socialist Workers Party and not the communists emerged as the leading left force.
Vacuuming is also a known tactic in the US. For example, in Los Angeles, the FBI heavily repressed the Black Panthers while aiding an ersatz black liberation organization, the US Organization, which it even helped to murder Panthers such as Bunchy Carter.
In fact, vacuuming occurs constantly in the US, on small, medium and large scales today.
The main way to respond to vacuuming is to not respond to it directly at all. There's rarely anything to be gained by pointing out how stupid the project actually is behind the shiny bits. The vacuumers must instead be out organized. You'll know you've won this round when the backwards people start coming to your events again.
The worst way to respond to it is to succumb to it, to give up whatever you have built — however small and fragile — to join this larger, exciting, but ultimately utterly sterile project.