Is there any specific reason why you're not accepting deposits from the US anymore?
There is not much to explain I guess,just the US laws.If you wish to read up on the topic,I found an archive :
https://archives.fbi.gov/archives/news/stories/2007/june/gambling_060607tl;dr you can gamble your life out at Vegas Casinos in America but it is illegal to gamble online especially if the gambling website is located outside of the US.
Will you be banning Belgian IP addresses too? AFAIK Belgian law also prohibits unlicensed casino's (unlicensed in Belgium) to offer their services to Belgian citizens.
That could be the case but it is least of their government's concerns.As far as I know they're okay with it only under one condition,
the main restriction lies in minimal age limits to enter premises or to participate in gambling activities.