The phrase "activists noticed" is correct and usable in written English.
It can be used when discussing observations or awareness raised by activists regarding a particular issue or event.
Example: "Activists noticed a significant increase in pollution levels in the river over the past year."
Alternatives: "activists observed" or "activists pointed out".
Friday, 2 28 p.m. Update: As a reader of The Lede pointed out on Twitter after this post was published, Syrian activists noticed that the frequent bystander had also appeared at the very start of a graphic video clip recorded just after the bomb attack in Damascus on Thursday.
After a blistering article attacking Kolata's reporting appeared in the Village Voice (Kolata calls it "the nastiest article I have ever seen in my life"), some activists noticed she was taken off the beat for a while.
About eight years ago, Toni Cox-Burns, a White Plains activist, noticed "an explosion" of reading groups among African-American women.
The activist noticed that hackers from China were using the network to gather foreign governments' information, and began to record this traffic.
The threats and attacks started after 26-year-old Brijmohan Yadav, a pudgy round-faced social and environmental activist, noticed suspicious activity on the riverbeds of the Betwa and Ken rivers near his home village in Bundelkhand, a drought-stricken region of central India.
Leaving the cabin of two environmental activists, Hochschild noticed a bundle of lawn signs for the local Tea Party congressional candidate, awaiting distribution.
Soon after the young woman was released by the Syrian government in a prisoner exchange, activists began noticing the signs.
He was first noticed in activists' gatherings in Brighton in March 2005 and became a regular face at meetings of Dissent!, the network mobilising protesters for the G8 summit at Gleneagles in July.
Is Michael Gove worried he may not be in power in September, scared that Liberal Democrat councillors and activists might finally notice that the coalition is rapidly smashing up their carefully crafted education policy or anxious that parents might rise up and object?
"The activist who did so immediately noticed their eyes burning, which led to the discovery that when carbon dioxide reacts with liquids or mucus-coated membranes it forms carbonic acid," it said.
Local news outlets and activists took notice, pointing to this figure as tangible evidence that ongoing campaigns to stem shark fin consumption in mainland China are working.
