Lindsay Lohan failed a drug test. How do we know? Twitter, of course.

"Regrettably, I did in fact fail my most recent drug test and if I am asked, I am prepared to appear before judge Fox next week as a result," the troubled actress tweeted. She was sprung from the pokey on Aug. 2 after a 13-day stay for a probation violation in a drug case.

Besides a possible return to jail, Lohan's latest legal troubles might endanger her ability to travel to film her next project, a biopic of porn star Linda Lovelace, TMZ reports.

A dual intervention for Lohan may be needed -- first for the drug problem, second for her choice of movie roles. Her lawyer also should be sure to check that her fingernails don't spell out an obscenity for her impending court appearance.