Wikipedia, the online encyclopedia, has blocked almost 400 accounts being used by people being paid to create or tweak entries.
Weeks of investigation revealed 381 accounts being used at the English version of Wikipedia for "black hat" editing in which people took money to promote outside interests without disclosing they were on someone’s payroll, according to a blog post.
Wikipedia editors who led the investigation found reason to believe that some tactics used were malicious and might even be considered extortion.
In some cases, people pretending to represent Wikipedia reached out to subjects of articles seeking payment.