US Denies Nigella Lawson Entry for Drug Use, Sets Precedent

According to numerous media outlets, Nigella Lawson was recently stopped from boarding a flight to the US on the grounds that she had admitted to cocaine use in the past. The US department of homeland security have even gone as far as to say that foreigners who admit to drug taking are deemed "inadmissible."
In light of this somewhat poorly thought out comment, it seems pertinent to look at just which high-profile non-Americans are now no longer allowed into the US due to their prior experiences with narcotics. A top 10 in no particular order seems fitting, but for more on celebrities and politicans who have dabbled, see Release's 'Nice People Take Drugs' playing cards, and Oh! Facts' top 20.
1. Justin Bieber
He is, in fact, Canadian and has been caught with marijuana within the past year. Kiss goodbye to your lengthy concert tours in the US Justin, you're never getting back in!
2. Keith Richards
Famously declared he had snorted the remains of his cremated father and "couldn't resist mixing him with a little cocaine."
3. London Mayor, Boris Johnson
"Of course I've taken drugs."
4. Sienna Miller
"I still love unusual hallucinogenic drugs. If I could have my pick, it would be magic mushrooms."
5. Australian Prime Minister, Tony Abbott
"I had a puff of a marijuana cigarette when I was a student."
6. Russell Brand
Has been more than open about his past experiences, yet the US have allowed him to spend a great deal of time over there. Something they may have to rethink in oder to back up their homeland security.
7. UK Prime Minister, David Cameron
The UK PM has been incredibly coy about any drug use in the past, leading many to speculate his lack of an outright denial - "I did lots of things before I came into politics which I shouldn't have done. We all did." - is an implicit admission. It probably is.
8. Colin Farrell
Reportedly told a psychiatrist that his intake in one single week was 20 ecstasies; 4 grams of cocaine; 6 grams of speed; 30 grams of hashish. Seems a little excessive, but regardless, he has done enough to be refused entry.
9. Naomi Campbell
Admitted to trying cocaine one time at a concert and that it made her feel "invincible." Not invincible enough to be allowed into the US now, though, I'm afraid.
10. Arnold Schwarzenegger
A tricky one since he is now an American citizen. Maybe the US could look into deportation, however. After all, he has admitted to using cannabis, and in his own words, doing "what I feel like doing."