This is an article written by Michael Hayden, an investigative journalist for the SPLC, documenting some of the tactics and strategies used in infiltrating and undermining various pro-White or ethno-nationalist platforms. It's worth a read to see some of the tactics employed by our enemies.

Some choice quotes:

Using Googles Advanced Operators
Google offers some in-house tools to help with digging for hard to find material. These are called search operators and there are many of them at your disposal. I would list them all here, but only a few of them have been useful to me in my work. The ones that have been useful, however, have saved me time and turned up things I would not have otherwise found.
Google provides an extremely useful tool for searching within websites, for example: Site:[website address] keyword. The tool is particularly useful with fringe social media sites that offer ineffective in-house search tools, like the white nationalist-friendly Twitter knock off Gab.
Heres one way I use that operator: Eric Striker is the pseudonym of a podcast host and Daily Stormer writer named Joseph Jordan who posted on Gab under the handles @estriker, @Eric_Striker, and @Eric_StrikerDS before dropping out of that site altogether in February of 2019. When reporting on Jordan for SPLC, I would put Eric Striker into Gabs search tool. The results Id get back would be chaotic, and of little use to my work.
To get around that I would type Eric Striker into Google, and bring up the @Eric_Striker handle with the first result. The search would also produce scores of his relevant posts. A more concentrated search, whites, for example, turns up specific posts wherein the user mentioned the word white or whites. The tool enabled me to bring up his Gab posts dating back to when he first joined that site.
For many Americans, its easy to ascribe a sense of permanence to the things they see and do online. Maybe they log onto a few major websites like Facebook, Twitter, and Instagram. Maybe they check their fantasy sports teams on corporate-backed websites like CBS or ESPN. Maybe they get a little information here and there about politics on Apple News. Maybe they do a little shopping, or take in a little pornography. Activists on both the left and the right would call people like this normies, implying that they arent clued into the minute details of 24/7 internet politics.
But on the fringes of the internet, non-normies are plotting to reshape normie opinions on urgent issues like immigration, health care, and war by pushing memes and other propaganda into their line of sight. Casual internet users may be unaware that these same people gather to hash out plans about them on obscure, often-clunky sites that have no sense of permanence. Ill call them fringe websites here, and they span sites like 4chan, which get hundreds of thousands of page views per day, to obscure forums that get attract eyes than the average tweet.
And on the fringes, there is far less permanence. Influential communities with thousands of users disappear overnight without a trace: The white nationalist forum The Right Stuff, which had just under 10,000 users, was reduced to a single thread in May of 2018 after its proprietors ran into legal trouble. WrongThink.Net, a say-anything Facebook clone with a large constituency of racist and anti-Semitic users, found the service down for maintenance following the Pittsburgh Synagogue shooting in October of 2018. The website never returned.
From the rise of populist right-wing figures like Trump and Brazilian president Jair Bolsonaro to the Brexit vote, words whispered on tiny forums like this have found their way into the mouths of people with real power across the world.

Tracking the Flow of Users from Fringe Networks
When The Right Stuff forum was reduced to one thread and its extensive history wiped in May of 2018, its white nationalist user base didnt diethey migrated elsewhere. Similarly, when Gab was taken offline for a week between the end of October and beginning of November in 2018 following the Tree of Life synagogue shooting, users regrouped on several different sites.
Tracking the migration of users from a disabled platform to new places online requires either offline connections to users of the original platform (so you can ask them directly about where theyre headed), or that you find activity that points to a migration.

A poster from The Right Stuff, for example, linked to a room on Riot as that forum was closing down. Riot is a messaging and discussion app similar to Discord, and two hours after that users post, the room went from non-existence to having several hundred people in it, discussing the fate of the white race, just as they had on the forum. Before Gab was briefly taken offline, users saw its demise coming. Some took advantage of Gabs waning hours before a shutdown to suggest they regroup on WrongThink.Net. But when WrongThing.Net began to see a number of controversial new arrivals, its proprietors abruptly and somewhat mysteriously took the website down for maintenance. Users then quickly recommended the cryptocurrency website, which is where high-profile Gab users like Christopher Cantwell, Microchip, and anti-Semitic politician Patrick Little ultimately reconvened in Gabs absence.
Fortunately, many pseudonymous participants in online forums enjoy the prominence they achieve in these communities and are loath to leave it behind when they migrate to a new service, so they use the same handles and avatars on different websites making them easy to find again. The neo-Nazi forum Iron March, The Right Stuff forum, and the Daily Stormers forum The Goyim Know, for example, featured many prolific posters whose pseudonyms and avatars also appear elsewhere. The use of the same name isnt indicative of a lack of creativity, necessarily. The users want their friends and fans to be able to find them.

  • Always make a note of conversations that indicate where users say they will move in the event of an emergency.
  • Keep an eye on high profile names on forums and websites and try to search for their handles elsewhere.
  • Check major websites like Twitter for conversations where people talk about reconvening on a different website by searching out the name of the original forum or website and scanning conversations about it.
Gaining Unfettered Access
While some forums and websites grant strangers total access, many others arent so generous, and require that you sign up for an account. Twitter, for example, requires that users log in to view another users history of replies (though the search operators described in chapter two will function whether or not a user is logged in). Fringe websites often require a login to use their in-house search functions.
Use your judgment about how you enter particular communities. For example, some websites require a vetting system. Fascist Forge, the neo-Nazi forum, requires essay-length submissions to the site to unlock part of it. Rooms on Riot and Discord may require vetting from a moderator. If you lie about who you are to gain access, your story may be ethically compromised, depending on the standards set by your publisher. Doing this can also create legal complications that simply telling the truth wont.
Unicorn Riot, an activist group, has published personal information contained in Discord logs from white supremacist groups after gaining trust and entry, but Unicorn Riots writers dont have the same legal requirements that are company-wide policy at a large media conglomerate like News Corp or ABC News/Disney. Check with your editor about how to proceed in situations where permission is required to read certain material published online. The last thing you want is to lose your hard work over regulations you werent aware of and could easily have followed.

Building Relationships with Online Communities
Whether or not Im getting juicy quotes is irrelevant to me in my work with the alt-right community, and its rare that I even quote those subjects in a story. Most of the conversations I have are off the record, in fact. And yet, despite the fact these chats dont help to fill in the details of a story, I chat with those posterspeople with whom Im not friends, mind youall day long on different apps. Why do this? (My therapist may have a different reply to this question but my professional answer follows.)
The reason reporters and researchers speak with members of any community daily is to be able to report with confidence about what motivates people within it. Even if its racist, sexist, homophobic or if it offends me, its useful for me to treat it as activism in my reporting whenever people are trying to use their computers to change the world in some way, big or small. To the extent that they succeed, thats newsworthy.
People who operate in this world daily can point you in the direction of new stories, and sharpen your understanding of a beat. Conversations like this can help you navigate breaking news, especially when someone with whom youve corresponded can direct you to something happening online that you might otherwise miss.
Heres what I recommend to help build relationships with subjects in hostile communities:

  • Use humor and language that your subjects will understand without using offensive words that could get you fired.
  • Try not argue or lose your temper. (This is not always easy. Talented trolls know how to make people angry.)
  • Never agree to debate someone on a subject or speak too personally about politics.
  • When you do offer an opinion, be reasonable, and make it clear that you are speaking for yourself and not your employer.
  • Be sincere about your desire to build a relationship. If you feel confident that you dont need a conversation on the record, say as much.
  • Avoid situations where the feelings of unpleasantness outweigh the potential gain of obtaining a new source.
The entire article is worth reading.