Sean Dickinson, an employee of Blackburn with Darwen Borough Council in Lancashire, sent several public figures offensive messages on Twitter.
At a tribunal at the Health and Care Professions Council, he was found to have committed professional misconduct.
He told the hearing in London he "bitterly" regretted his actions.
Panel chairman Penny Griffith said the "obscene" comments brought the social worker profession into disrepute.
"The panel accepts that there was no law against being rude or unpleasant," she said, but "there are responsibilities and standards which are voluntarily accepted and adopted by professionals".
Mr Dickinson also launched an attack at media mogul Rupert Murdoch and tweeted that burglars "are vermin and should be shot".
Ms Griffith said the comments "have brought the profession into disrepute".
Mr Dickinson told the hearing he was "going through a very dark period" when he posted the offensive comments in 2012 and 2013.
He is currently employed as a senior social worker for the council and said he has been given additional managerial duties since the incident.
He said: "I look back on it and can't believe it was me who wrote those things and in that way. I bitterly, bitterly regret it."
The hearing continues.
A senior social worker who launched an abusive social media campaign against David Cameron and Donald Trump has been found guilty of misconduct.