If you like to gamble with your skins on Team Fortress 2 sites, be very careful, as Valve is looking to ban any and all Steam accounts associated with such sites. That could mean you end up being caught up in the ban wave, or at least have your items lost as they are banned mid-trade.
Valve took a lot of flak from parents and gamers alike in 2016, after it became mainstream news that many sites existed which allowed gambling of one's CS:GO skins. There were no age gates on these sites and although not officially affiliated with Valve or Steam, the use of CS:GO items made it seem so and certainly reflected poorly on Valve because of that.
That's why Valve cracked down on those sites, banning associated accounts and moving to have the sites themselves shut down. Now, with gamblers and site owners moving on to other games to try and keep the money train rolling, Valve is banning new accounts associated with Team Fortress 2 gambling.
It's highlighted once again that it doesn't support these sorts of sites and will continue to try and have them shut down. They do technically operate illegally because they allow gambling without a gambling license and do not implement proper age checks.
An extra layer of nefariousness was added to these sites when in 2016 it was discovered that many of those who advertised them on popular gaming Youtube channels, claiming that they merely played on them, were actually owners of the sites themselves. They scammed their viewers for money.
Valve wants to make sure that doesn't happen in the future.
