Photos apparently stolen from Emma Watson, Amanda Seyfried and other female celebrities have been posted on 4chan and Reddit, drawing comparisons to a 2014 hack, grossly dubbed “The Fappening” that exposed nude photos and video of several celebrities. The hacker in that case, Ryan Collins, obtained the pictures from iCloud accounts via a phishing scheme and was sentenced last fall to 18 months in prison.

The images range from benign snapshots from clothing fittings to sexually explicit material. Several of the posts alleged that photos of other women might be leaked, as well.

“Photos from a clothes fitting Emma had with a stylist a couple of years ago have been stolen. They are not nude photographs. Lawyers have been instructed and we are not commenting further,” a spokesperson for Watson told the BBC.

After addressing the United Nations about gender equality, Watson said in 2015 she was threatened with a leak of nude photos. “I knew it was a hoax. I knew the pictures didn’t exist,” she said. “If anything, it made me so much more determined. I was just raging. It made me so angry that I was just like … ‘This is why I have to be doing this!’ … So if anything, it actually, if they were trying to put me off it, they did the opposite.”

Phishing scams have been behind several high-profile hacks, including that of Clinton campaign manager John Podesta during the 2016 election cycle. Hackers trick victims by sending links that appear to be from email providers that ask victims to enter their login details. The usernames and passwords are then stolen and used to log in to victims’ accounts and back up their data.

The methodology used here is not yet clear, but chatter on the 4chan message board, where many of the images began to be posted on Tuesday, indicate that they’re coming from private image sharing groups. Private groups of phisher/hacker collectors were involved in the last major celebrity hacking, as well. Salacious images of public figures tend to get traded around amongst these collectors and used as currency to expand their private stash.

Every once in a while, dumps of these images spill over into the mainstream, triggering public attention and investigation.