The Kolkata Police have arrested a 24-year-old engineer, Agniswar Chakraborty, for posting a sexually explicit threat on a woman’s Facebook profile picture.

The police said Chakraborty had admitted his guilt, after which criminal proceedings were initiated. His mobile phone has also been seized, the department tweeted on Tuesday.

Joint Commissioner of Police (Crime) Vishal Garg said officers had acted on a complaint from the woman, who is currently studying in Australia, The Times of India reported. “He had outraged the modesty of the victim by posting sexually explicit comments on Facebook and used a 27-week-old profile picture to comment,” Garg said, adding that this shows Chakraborty had probably been stalking the woman online for sometime.

Activist Pranaadhika Sinha Devburman, who helped the woman lodge the complaint, said Chakraborty had commented on a picture of the woman speaking with her younger brother on Skype with the caption “I miss you. You’re my best friend”.

The accused first posted an emoticon, but the woman deleted the comment as she did not know him. What followed were a series of rape threats to her and her brother.

A change.org petition with 32,700 supporters has demanded that the Kolkata High Court set an example by punishing Chakraborty the strictest possible way. “We cannot simply let someone get away with a toxic mentality as such,” the petition said, adding that threatening a woman with such words should attract the punishment that raping someone does.