Cildo Meireles a Brazilian conceptual artist calls his interventionist works Insertions into Ideological Circuits. For example printing "Yankee Go Home" on a coke bottle that simply gets sent back in the bottling plant washed, refilled and put back into circulation. The commercial company distributes for Cildo his criticism of its own global domination. The Tate has a nice website about their retrospective of his work.
We also looked at other artist interventions. Watching Sonic Outlaws by Craig Baldwin which included the likes of Tape-beatles (who are still working together)John Oswald with his plunderphonics and others all addressing Negative Lands problems with U2 (who naturally are also online at http://www.negativland.com/.