The truth, though, is that it is possible that the Weiner-wiener incident was pulled off by pranksters who knew how to manipulate yFrog into posting a photo to Weiner's account. yFrog, like many other image services, allows users to send a photo to a specialized e-mail address made for that person's account; when the service receives the message, it gets posted automatically and then tweeted out to the world.
The yFrog e-mail addresses given to users aren't public, but they also aren't hard to crack with some patience and some brute force. As noted by the Daily Dot, the format includes the user's twitter name, a period,
and a random word between five and six characters @yfrog.com (for example, mine might be something like
ejacqui.bears@yfrog.com).
And because yFrog apparently accepts submissions to those secret e-mail addresses from any account, any prankster who has guessed the random dictionary word could send a photo to Weiner's account as if it were from Weiner himself.