You can hack some random accounts in facebook and myspace
Lets take a example of Myspace
go to Myspace website and search for a user "familiarname"@mailinator.com
here i typed email@example.com in the search box (search people)
IF you are lucky you will get to find a user with an account like this
now go to Sign In and type forgot password
Type the Email ID (firstname.lastname@example.org) and captcha
after that you will get a confirmation that the password reset is being sent to you
Now visit www.mailinator.com type the email ID you just entered( email@example.com in my case) and check the Inbox you get a link to redirect to RESET PASSWORD change it and BINGO !!
you successfully hijacked the account !!