Social media platforms play a massive role in driving 21st century protests. While networks like Twitter are widely recognized as primary catalysts for political activism, empirical quantitative data remains limited regarding Facebook's ability to mobilize physical protest turnout in Nigeria. To address this critical academic gap, this study investigated how sharing specific content on Facebook, such as police victimisation scenes, economic hardship scenarios, and protest situational reports, correlates with actual participation in the historic 2020 End Special Anti-Robbery Squad (#EndSARS) movement in Nigeria. Using a survey-based quantitative design, the study analysed statistical relationships across a broad sample to ensure the insights accurately reflect the larger target population. The findings reveal that sharing situational reports and clear evidence of police victimisation significantly expands active demonstrations by drawing more citizens to active protests. Conversely, sharing stories about economic grievances showed no meaningful connection to immediate physical turnout. Based on these insights, the study recommends careful platform moderation during active civic unrest to discourage highly inflammatory posts that rapidly worsen conflicts. Ultimately, this specific research offers a fresh perspective on digital activism, proving that Facebook is an essential catalyst for modern social movements.