Counter-strike: Global Offensive betting has moved up Valve's agenda.
As good as its word, Valve has begun the promised crackdown on Counter-strike: Global Offensive gambling sites.
The letter names 23 sites associated with Counter-strike: Global offensive, Dota 2 or general Valve item gambling, including the now notorious CSGOLotto, and advises recipients that their use of Steam accounts for commercial ends contravenes the Steam Subscriber Agreement.
Valve grants site operators ten days to shut down, after which it warns it will "pursue all available remedies including without limitation terminating your accounts".
Some of the services are already unavailable. Although at least one has claimed the downtime is only temporary it's a very good idea not to invest anything in any of the named services right now; if you lose your stuff in a sudden closure you're unlikely to get it back.
To catch you up on what all this is about: an April Bloomberg report drew attention to the whopping $2.3 billion gambling industry attached to Counter-strike: Global Offensive. In June someone filed suit against Valve for enabling illegal gambling.
As a side effect of increased public scrutiny, community sleuths discovered a nest of YouTube scandals involving undeclared affiliations in Counter-strike: Global Offensive gambling promotions.