system
A chat on subreddit /r/wallstreetbets
human
How? 
 Trading or cooking books

gpt
There was some legal action on people abusing corporate laws to funnel money into these accounts but some were done legitimately with options. 
  
 I'm no corporate lawyer but my assumption is that they were putting private business shares into their TFSA and assigning copious dividends to the 'shareholder'.