Twitter is denying claims that its employees routinely monitor private data and Direct Messages. The video that appears to show twitter employees making claims about what they've seen is selectively edited, but it does raise concerns. Twitter's response was of denial.

a Twitter representative said “we do not proactively review DMs. Period. A limited number of employees have access to such information, for legitimate work purposes, and we enforce strict access protocols for those employees.” Twitter Denies Routinely Monitoring Direct Messages [techcrunch.com]