Emile Hirsch has poked fun at Shia LaBeouf on Twitter.

The 'Lone Survivor' actor mocked his former friend in a series of sarcastic messages on Wednesday (12.02.14), just one day after the 'Transformers' star launched his new art installation, titled '#IAmSorry,' at a gallery in Los Angeles, which involves him sitting at a table in silence with a brown paper bag over his head printed with the words ''I Am Not Famous Anymore.''

Emile, 28, tweeted: ''I AM NOT FAMOUS TO BEGIN WITH.''

Soon after he added: ''I AM BEGINNING TO FEEL SLIGHTLY MORE FAMOUS,'' before writing: ''I TAKE IT BACK, STILL NOT FAMOUS.''

He later posted: ''I AM...CONFUSED ABOUT HOW FAMOUS OR NOT FAMOUS I MIGHT POTENTIALLY BE...ANYMORE...

''I AM...ACCIDENTALLY ON CAPS.''

A number of other celebrities have also teased Shia, who wore the same brown bag over his head to the Berlin premiere of 'Nymphomaniac' on Sunday (09.02.14), shortly after storming out of a press conference, and has tweeted the words ''I Am Not Famous Anymore'' almost every day since January 13, for his eccentric behaviour recently, including Jim Carrey, Lena Dunham, Billy Murray and Seth Rogen.

The 27-year-old actor announced last month that he was ''retiring from all public life'' after he was forced to apologise for plagiarising author Daniel Clowes' graphic novellas, 'Justin M. Damiano,' for his short film 'HowardCantour.com'.