Okay, on the Earth Liberation Front.
I won't bore you all with a potted history, the Wikipedia entry does a good enough job.
But as far as their connections with EF! go they were initially a "flag of convenience" for some in EF! To carry out acts of sabotage that EF! Itself couldn't or wouldn't.
There was more to it than that of course. Many EF!ers carried out sabotage regardless without using the ELF as cover, and activism (both overt and covert) was not the sole preserve of EF! Many within the movements developed something of an antipathy towards EF! and the trend in some quarters to lump all Eco-direct action under its umbrella.
At the same time not all ELFers had anything to do with EF!
Meanwhile the ALF IME generally didn't think much of the ELF and kept their distance in the main. The majority of overtures were one way. That didn't stop bother the state/media and the likes of green anarchist trying to link the two groups.
Initially it was Green Anarchist and it's periphery that perpetuated the idea of an ELF ( anyone remember the one off zine Terra-ist?
For example) but soon with the rapid growth of the Eco direction scene it became more of a real thing, however ephemeral...
I'm only talking about the "second wave" ELF (from around 93 onwards when it took on a life of its own away from GA fantasy) n the UK here. I don't know as much about the initial "group" supposedly formed in 92 nor any newer variants post Seattle. The USA is a whole other kettle of fish entirely too.
There does appear to be some use of the name amongst the same circles as the informal anarchists. A 3rd wave of the ELF perhaps?
Was it ever an actual organisation? Not really, they did attempt to replicate some of the more official structures of the ALF with press offices and prisoner support groups etc. but IME was more of an ad hoc flag of convenience for a small number of affinity groups and during particular struggles as and when.
Hth.
Obvs this just what I saw at the time, others experiences may differ...