Anne Hathaway wasn’t the Rat that got Anne’s ex boyfriend busted by the FBI; it was his former administrative assistant.
Follieri’s assistant told the FBI that Follieri kept a safe full of financial and business records in his Trump Tower apartments…err Anne’s Trump Tower apartments see this post.  According to the New York Post:
The court papers [...]

Anne Hathaway talks about her ex boyfriend/con man Raffaello Follieri in an interview with W Magazine. Anne talks about her life since the arrest in an interview stating:
“As soon as I found out about the arrest, I had to get on a plane to Mexico to do a press tour for Get Smart. And then [...]

Anne Hathaway I guess never “got smart” and allowed her boyfriend to rain “havoc” on her bank account.  The New York Post states that Anne was covering 37k a month for rent for her ex-boyfriend Raffaello Follieri’s apartment. 
This board spent her well worked for movie earnings on his apartment in the Olympic Tower while [...]

Anne Hathaway and four year boyfriend, Italian businessman Raffaello Follieri have split.
A source close to Anne Hathaway says in regards to the couple
for now, not together.  They are always breaking up and getting back together, so the fact that they broke up this time around doesn’t strike me as anything new. 
Follieri could also be doing [...]