"That '70s Show" actor Wilmer Valderrama has joined the list of many celebrities that have fallen victim to Twitter hackers.

The 34-year-old actor's Twitter account was hacked, and instead of a silly Twitter message posted up on his timeline, Valderrama's nude photos of "Give Your Heart a Break" singer Demi Lovato were put on display for all of the Twitter-verse to see.

Yikes!

The Daily Mail reported that the leaked photos included images of Lovato, 21, posing topless, another of Lovato lying completely naked in bed and a final photo of the 21-year-old singer and Valderrama french kissing.

These are reportedly the same images that were leaked of the couple back in April of this year.

If leaking the intimate photos of the couple wasn't cruel enough, the hacker then tried to poke fun at Lovato by posting a "Powerpuff Girls"-inspired photo in which a hulking figure labeled "Demi" towered over "Miley," "Ariana" and "Selena" along with the caption, "Shes fat as f***," FOX Latino reported.

Immediately following the Twitter hack, Valderrama tweeted, "ATTENTION EVERYONE! Someone just hacked my twitter account!!!!!"

And to ensure his privacy, as well as Lovato's, Valderrama even went as far as deleting his Twitter account altogether.

Another celebrity to endure a cruel Twitter hack this week is "Glee" star, Chris Colfer.

Last Thursday, while the 24-year-old actor was on a flight, a hacker managed to get into his account and tweet from his verified Twitter profile.

"Due to personal issues, I have been let go from the cast of GLEE. Explanations will come shortly ..." the hacker tweeted.

Since the hacked "Glee" tweet, Colfer's reps have gone on record to deny the false tweet.

"It appears his Twitter was hacked," Colfer's reps said in a statement. "He's on a flight and he will be returning next season. Fans, don't worry."

As more and more celebrities seem to be affected by Twitter hacking, the question that remains is what should be done to ensure the safety and privacy of celebrities online? Share your ideas and comments with us below.