dveykus613,
” I do think the American rabbonim did not because they don’t want to make a psak that “h’olam lo yachol la’amod bahem”
Agreed.
As far as filtering, the venishmartem website gives the various filtering options for smartphones. I think it’s poshut that there is no way any sane person could think that having unfiltered internet on his phone could possible be ratzon Hashem. There no way that 99% of people won’t be nichshal. “Ma yaaseh haben velo yecheto”.