Of course going online during the Sabbath is a clear violation for Jews. Gentiles are not required to keep the sabbath.
On the other hand, as King Solomon said so many thousands of years ago, "There is no man (or woman) so righteous that he (or she) never sins." To quote JESUS here even though I reject him as anything other than a philosopher, "Let he who is without sin, cast the first stone."
While a Jew is required to keep the Sabbath, I do think that how we treat each other is far more important. G-d Himself has no needs, and cannot truly get hurt no matter how we treat Him, but our fellow human being is infinitely more vulnerable and can get hurt quite easily. Better to be around a kind person whose theological beliefs may be questionable, than around a very strong believer in G-d who acts like a jerk.