I’m not aware Beck has been visited by the secret service for comments about Obama.
However I do know that back in March that he and his radio show co-hosts were interviewed by the secret service over his stabbing Trump comments. If they need to visit Beck yet again over this latest Trump assassination fantasy talk, it will be much more serious and Beck will likely receive at least a strong warning to knock off the assassination talk and reminder that his 1st amendment free speech rights do not extend to assassination talk about a secret service protectee.
I’m pretty sure I remember him talking about a visit from the Secret Service or somebody a couple of years ago, maybe it’s been longer. He described them as being apologetic about the visit because they knew that the threat was groundless and they understood he was joking when he said whatever he said that triggered the visit.