New York (CNN Business) Mark Zuckerberg last week invoked Black Lives Matter in explaining why he believes it's so important to allow free expression on Facebook. But real black activists remember how Facebook ( FB ) allowed its platforms to be used to take advantage of BLM and African Americans, standing by as Russian trolls created fake pages and events and allowing for the biggest BLM page on the site to be a scam run out of Australia. They don't trust Facebook to stop that from happening again and so they are taking the fight into their own hands.

"Look for accounts that post and retweet in unnatural patterns," Black Lives Matter advises activists in new guidance on its website . "Some fake accounts are scripted to post 24 hours a day 7 days a week, with no sleeping.

"Also, be wary of accounts and those who claim to be in the US, but almost always post from a non-US based time zone," it adds.

Lessons from 2016

Some activists have been exercising such skepticism for years — long before Facebook began doing so.

In the hours after Philando Castile was killed by police in Minnesota in July 2016 local activists became suspicious of an ostensibly black activist page that began organizing an anti-police protest.

It emerged more than a year later that the page, which was called "Don't Shoot" and had more than 250,000 followers, was run from St. Petersburg, Russia, and part of a Kremlin-linked campaign that exploited black activists in an attempt to exacerbate racial divisions in the United States.

The Russians ran multiple Facebook pages designed to look like they were tied to Black Lives Matter and paid Facebook thousands of rubles to target ads at African Americans and even recruited unwitting black activists to work for them

The biggest Black Lives Matter page on Facebook was also a fake.

That page, which had nearly 700,000 followers, was linked to a white man living in Australia and ran fake fundraising that brought in at least $100,000. People donating thought their money was going to Black Lives Matter campaigns — instead, the funds were being transferred to an Australian bank account.

A movement, targeted

Alicia Garza, a co-founder of Black Lives Matter, said she was "enraged" when she heard Zuckerberg invoke the movement in his speech last week in Washington, D.C., which was billed by Facebook as being about free expression.

"Movements like Black Lives Matter and Me Too went viral on Facebook," Zuckerberg said. "[T]his just wouldn't have been possible in the same way before."

But Garza believes Facebook hasn't done Black Lives Matter any favors. "What they care about more than civil rights is their bottom line," she said.

Black Lives Matter hopes its new in-house initiative, where activists from across the country can report suspicious pages, will help avoid a repeat of 2016.

When an activist reports suspicious online activity, the movement's digital security team will investigate and, if warranted, bring it to the attention of the relevant social media company

Since 2016, Facebook has implemented new policies that are meant to help prevent Russians from buying political ads targeting activists; added new page transparency rules that show where some pages are operated from; and has hired a team that includes former intelligence officials to root out and shut down fake campaigns.

But Kailee Scales, director of strategic partnerships at Black Lives Matter, told CNN Business that all social media platforms need to do more to help activists. "We need them to value and protect organizers as much as they do advertisers," she said.

"We understand that, as history shows us, organized disinformation is a tried-and-true way to undermine the work of black organizers, bring harm to us, and bring chaos to our communities," she added.

A bipartisan report released earlier this month from the Senate Intelligence Committee on Russia's use of social media to interfere in the 2016 election and American life found that no group of Americans was targeted more by those operations than African Americans.

Earlier this week Facebook removed networks of fake accounts posing as Americans that were run separately from Russia and Iran — both the Russian and the Iranian campaigns included accounts that posed as black activist groups.

Scales said people need to "understand the impact of disinformation on the work of black liberation — that our messages are being co-opted and misappropriated by international actors attempting to cause chaos and disorientation in this country."

Some progress, still enabling

Further antagonizing some activists is Facebook's policy of allowing politicians to lie in ads they run on the platform and Zuckerberg invoking Martin Luther King Jr. in his speech last week.

Arisha Hatch, a vice president at Color of Change, America's largest online racial justice organization, has regularly spoken with Facebook as part of the company's drive to improve its platform for activists. Hatch said she believed Facebook had been making some progress in the area but that a lot of the good work had been undone by the company's recent reaffirmation of its policy of allowing false ads from politicians.

"This notion that a politician should be held to a lower standard than the rest of their users is disgraceful," she told CNN Business.

Hatch said the policy made Facebook an enabler of misinformation and that the policy had "emboldened the civil rights community" to speak out against the company.

Bernice King, the daughter of Martin Luther King Jr., previously blasted Zuckerberg for pointing to her father.

"I heard #MarkZuckerberg's 'free expression' speech, in which he referenced my father. I'd like to help Facebook better understand the challenges #MLK faced from disinformation campaigns launched by politicians. These campaigns created an atmosphere for his assassination," King tweeted

Zuckerberg, who reached out to King after the tweet, told reporters on a press call earlier this week that "I think she's right that these issues around hate and disinformation likely played a role in the environment around his assassination, and those are big issues and that's why we work hard to fight them in everything that we do."

"At the same time, one of the things that I find inspiring is that through everything that Martin Luther King Jr. went through, he never lost faith in the importance of free expression," he added.

A Facebook spokesperson told CNN Business on Wednesday, "Our partnership with civil rights groups has led to important progress on issues such as voter suppression, hate and discrimination in ads on Facebook. We'll continue to actively engage and seek input from the civil rights community to address concerns about our policies and products."