Complex sentence: Although never an official member, Ron several times joined with the Billboard Liberation Front, which practices culture jamming by altering billboards by changing key words to radically alter the message, often to an anti-corporate message.
Split into simpler sentences: Although never an official member, Ron joined forces with the Billboard Liberation Front on several occasions. The B.L.F. practices culture jamming by altering billboards by changing key words to radically alter the message, often to an anti-corporate message.