The petition that was supposedly blasting through 3 million signatures 3 days after the Brexit vote, is acknowledged to have been filled with fraudulent signatures added by bots.
Source: EXCLUSIVE: Brexit ‘2nd Referendum Petition’ A 4 Chan Prank: BBC Report It As Real | Heat Street
The BBC has updated their news report to indicate the petition may contain “suspicious activity” and that fraudulently added signatures have been identified.
Fake news runs rampant thanks to social media enabling anyone and everyone to become a propagandist!
Fake news is always common after an “event”.  So far, we have:

• The not really a spike, “spike in Brits searching for  What is the EU?” fraud
• The fake 2nd referendum petition fraud

I have examples of similar frauds that have occurred during or after other events. Time permitting, I will post some of these soon – they illustrate how easy it is, particularly with social media, to bend reality and influence populations.