Law enforcement sources tell us ... deputies responded to a call from Schroder Sunday and stopped by his home to review various negative social media posts directed at the "NYPD Blue" actor.

While they weren't life-threatening, some of the comments were pretty nasty ... "Tbh thought he was dead. Would've been better," "This was a racist move pure and simple," and "Ricky Schroder can shove that silver spoon right up his own ass."

Celebs including Bette Midler weighed in too, saying, "Who knew he could be so malevolent?"

We're told cops determined none of the online comments rose to the level of a criminal threat ... so the officers just took a suspicious circumstances report and left.

Our sources say Schroder will be in contact with authorities if things escalate, and we're told police are monitoring the situation.

As we reported ... Schroder donated $150k to the 17-year-old's bail fund, which the teen's attorney, Lin Wood, said helped them post $2 million bail to get Rittenouse out of jail while he awaits trial for murder.

Some of the outcry is obviously harsher than others ... but you get the idea.