There is no public information on how much he was paid for these lectures or who was present, but as the Clintons example showed, lectures in foreign countries can result in very large fees. According to one source the later President of the European Council, Herman Van Rompuy of Belgium was present on Malta at the same time.
http://www.texemarrs.com/072012/roberts_lauded_by_knights_of_malta.htm
The interesting thing about Malta is that it is a major offshore banking location. It is one of the top ten locations for offshore banking. Banking arrangements for non EU individuals takes about two weeks - the length of time Judge Roberts visited. Even though he only gave 6 lectures, he stayed long enough to set up an account.
ping
---snip--
Mueller's staff of lawyers, Republicans showed, reads like a donors list for Hillary Clinton.
The FBI contingent that started the investigation was a cabal so hateful of Trump that some had to be fired.
Republicans raised questions about the origins of the investigation, tracing it back to early 2016 when Maltese intelligence agent Joseph Mifsud leaked to a staffer of the Trump campaign, George Papadopoulos, that Russia had Clinton's emails.
That and subsequent meetings have all the marks of an intel agency set-up.
Repeatedly, Republicans brought up the dossier written by British spy Christopher Steele, who fed Russian-sourced disinformation to Clinton campaign-financed intel firm, Fusion GPS, who passed it on to the FBI, which used it as evidence to justify warrants to spy on Trump's campaign.
--SNIP--