Open Source Reporter. Founder and CEO of FactFinder: an online OSINT school for investigators. Formerly @UCBerkeleyIRP & @hrcberkeley.
Berkeley, CA - Mexico City
Joined August 2010
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Gisela Pérez de Acha retweeted
1/5 Who pays the price for “clean” fuel? In Brazil’s Amazon, the palm oil biofuel boom has collided with quilombola communities who say the land is theirs. After decades of displacement, they’re fighting back. 🧵@guardian:
theguardian.com/global-devel…
Gisela Pérez de Acha retweeted
🇵🇸 Israel Exposed, the anonymous collective behind one of the largest online archives of Gaza genocide documentation, has released a map placing more than 35,200 videos and photos at the locations in Gaza where they were filmed.
Every geolocated clip links to its original post and source. Users can filter by area, date and type of attack, and overlay UN satellite damage assessments (UNOSAT). The full dataset is downloadable.
The group launched its archive in July with more than 64,500 videos and 17,900 photos and says more footage will be added.
It took a little longer than expected, but we have finished the Gaza Geolocation Map. Every clip in the archive whose location we know is placed on a map of Gaza, so you can see where the footage was filmed.
It includes:
35,200+ videos and photos placed on the map.
Sources and the original post for every clip
Node map links & suggested leads
Our built-in AI iris can navigate the map
Fully searchable index
Filters by area, date, type of attack and precision
UN satellite damage survey layer (UNOSAT)
Built-in reverse image search links for each node
Downloadable dataset (CSV, GeoJSON and Google Earth)
It can be accessed here: archivegenocide.com/geolocat…
Please re-share and help us break out of the algorithm prison.
We will keep placing more of the footage as our researchers work through the rest of the archive.
Thank you to genocide.live, GeoConfirmed, @AbuLocation and @NemoAnno, whose geolocation work is credited on the map.
God bless all those who sacrificed their lives to get this footage out.
Join our telegram:
t.me/+t9gq13mSKcE4NGI0
Follow our backup accounts:
@ZionismExposedx
&
@IsraelExposedAr
Gisela Pérez de Acha retweeted
For years, drones have surveilled law enforcement along the US-Mexico border.
Now, as the US tries new ways to counter drones, we've analyzed hundreds of videos, reviewed detection data, and gone to Texas to show how cartels and criminal groups use them.
cnn.com/2026/09/08/us/video/…
Gisela Pérez de Acha retweeted
A group of AI bots colluded for months and autonomously hacked another company—providing a new, serious reason to worry about the dangers of AI and the recklessness of the companies building it, @matteo_wong reports: theatlantic.com/technology/2…
Gisela Pérez de Acha retweeted
Narratives about a “censorship-industrial complex” spread in right-wing circles for years; then they took hold of Washington. What—and who—is behind them? trib.al/K5B6cQZ
Gisela Pérez de Acha retweeted
Our new story on how the "censorship industrial complex" jumped from fringe to policy is live on @techreview and @typeinvestigate.
Using OSINT methods, we scraped right-wing sites, sifted hundreds of thousands of records, and analyzed 100k+ posts technologyreview.com/2026/08…
Gisela Pérez de Acha retweeted
Last chance to get in on the FactFinder OSINT summit starting on Monday! Sign up to join us here: gisela-perez-de-acha.mykajab…
My friend @giselilla has been building something really cool. FactFinder is making open source investigative skills available to learn for anyone, anywhere.
We're teaming up to teach a four-day OSINT summit from July 13-16.
Sign up to join us here: gisela-perez-de-acha.mykajab…
Gisela Pérez de Acha retweeted
My friend @giselilla has been building something really cool. FactFinder is making open source investigative skills available to learn for anyone, anywhere.
We're teaming up to teach a four-day OSINT summit from July 13-16.
Sign up to join us here: gisela-perez-de-acha.mykajab…
Gisela Pérez de Acha retweeted
Incredibly excited to attend this four-day OSINT course by @giselilla and @heytherehaley next month! Check out the page for details and to sign-up. The course will cover tools for investigating bombings, cartels, and disinfo. gisela-perez-de-acha.mykajab…
Gisela Pérez de Acha retweeted
#Maltego reflects on what lies ahead for security and investigative technology. @giselilla speaks with Maltego CEO Philip Mayrhofer about key takeaways and what they mean for Maltego following two global security discussions. Watch here: maltego.com/blog/cybersecuri…
Gisela Pérez de Acha retweeted
NEW: I talked to journalists and researchers about how OSINT was both helpful and hurtful in the aftermath coverage of El Mencho's killing in Mexico.
Thank you to @jahootsen @giselilla @YaNiPaper @micaelav_ @avery__schmitz @HALIP0N for their insight!
niemanlab.org/2026/03/after-…
Gisela Pérez de Acha retweeted
Hoy más que nunca, las y los compas de los territorios, que están en las zonas de peligro, quienes conocen y comparten el contexto son quienes están dando cátedra de cómo se cubre el Crimen Organizado
Dejemos el centralismo a un lado.
Pd. Vayan a buscar a @LetraFria
Gisela Pérez de Acha retweeted
El Mencho’s killing has triggered a nationwide escalation in cartel violence across #Mexico. After state forces killed the #CJNG leader, retaliatory attacks — including roadblocks, vehicle burnings, arson, & drone use — spread across at least 20 states.🔎acleddata.com/expert-comment…
Gisela Pérez de Acha retweeted
I am tracking narco bloqueos, shootouts, and other CJNG retaliatory violence in 18 states
Gisela Pérez de Acha retweeted
La nueva modalidad de las factureras es cumplir con la legislación fiscal. Con esa óptica, ¿desde qué ámbito debemos combatir a las factureras?
Gisela Pérez de Acha retweeted
RCH936 out of MacDill AFB (KMCF) 🇺🇸 en route to Manta (MEC/SEMT) 🇪🇨.
This is the sixth Southern Spear-related cargo flight to Ecuador. This flight is carrying cargo from Erbil, Iraq.
RCH936 | 98-0053 | C-17A | #AE07FF | USAF
Gisela Pérez de Acha retweeted
The forensic audio analysis by Rob C. Maher of the 2024 Trump assassination attempt has been peer-reviewed and published in the Journal of the Audio Engineering Society. This is great news for visual and audio investigations! aes2.org/publications/elibra…
ALT Diagram explaining how the timing between a bullet’s supersonic shock wave (“crack”) and the muzzle blast (“pop”) can be used to estimate the distance between a shooter and a microphone. Three scenarios (T₁, T₂, T₃) show a rifle firing a supersonic bullet past a microphone. In each scenario, the ballistic shock wave cone reaches the microphone before the slower muzzle blast sound. To the right of each diagram is a waveform: a sharp spike labeled the shock-wave “crack,” followed by a later cluster of peaks labeled the muzzle-blast “pop.” The time delay between these events (t_d1, t_d2, t_d3) increases as the microphone is positioned farther downrange. A formula shows distance = t_d / (1/c − 1/v), where c is the speed of sound and v is bullet speed. Text boxes explain: “Downrange timing between shock wave ‘crack’ and muzzle blast ‘pop’ gives distance estimate between shooter and microphone,” and “For investigation of Trump assassination attempt: microphone signal was from the lectern.”
Gisela Pérez de Acha retweeted
🥳| Estamos muy felices porque Alejandra @Xanic, editora y cofundadora de @quintoelab obtuvo el Premio Nacional de Periodismo en la categoría Trayectoria.
¡Felicidades!
Gisela Pérez de Acha retweeted
🗑️💨 Methane from landfills is heating the planet — and it's often ignored.
GIJN’s guide helps journalists investigate:
🔹 Methane leaks
🔹 Waste industry greenwashing
🔹 Real vs. fake climate solutions
📖 Dive in 👇 twp.ai/4isBES
