They have been acting "risky" for a long time:
- Treating publishers badly
- Little to no meaningful support
- Ignoring feature requests (or asking to make a business case for feature requests ;-)
- 100% intransparency (no way to check what they pay to publishers)
- No policing of ads or advertisers
- Insufficient tools to filter ads or advertisers
I'd love to see Microsoft taking advantage of these weaknesses.