EMMA ALBERICI, PRESENTER: The police in New South Wales are warning there are limits to how far they can go to track down internet trolls after two feminist campaigners were attacked on Twitter and on Facebook. The women were threatened with rape and violence by internet users in Australia and overseas after campaigning against an American rapper and a Welsh football player convicted of sexual assault.

This story was produced by Candice Talberg and John Stewart. It contains confronting language.

JOHN STEWART, REPORTER: Tyler the creator is an up and coming rap star.

(Sound of a Tyler rap song)

JOHN STEWART: In June last year he toured Australia and feminist campaigner Talitha Stone protested against his use of language, which included rape and violence against women. She then received a flood of abuse from the rapper's fans on Twitter.

TALITHA STONE, FEMINIST CAMPAIGNER: I had people saying that I needed to be raped, that it's feminists like us that deserved to be raped.

JOHN STEWART: Last month Katelyn Roper, a feminist campaigner based in Perth, shared a petition against Ched Evans, a Welsh footballer who was convicted of rape, urging soccer teams not to rehire him. She was also inundated with Twitter abuse and threats of rape.

CAITLIN ROPER, FEMINIST CAMPAIGNER: So it had my picture and what looked like my Twitter handle alongside my name and everything else was the same, except he had included a graphic list of sex acts that I had performed for men online.

JOHN STEWART: Both women received threats which appeared to come from within Australia and overseas. They want the police to track down the Twitter users responsible for the abuse around the world. The West Australian police are currently investigating Ms Roper's complaint, but she's not happy with their advice.

CAITLIN ROPER: So the expectation was that women and me, that we should all further restrict our freedoms and close down our accounts, just cease from engaging in social media and that was the expectation, that rather than focussing on the perpetrators of the threats, the people making the threats and engaging in the abusive behaviour, that the victims, we should modify our behaviour.

TALITHA STONE: I was then handed cyber safety brochures and told that I had to delete any Twitter account, that I'm fuelling this.

JOHN STEWART: Social media commentator Stilgherrian say women using the internet experience more online abuse than men, however he says many users are still coming to terms with the reality of the net.

STILGHERIAN, SOCIAL MEDIA COMMENTATOR: It's simply that within the past people were in communities, that were mostly made up of people like them or people they grew up with. If there was a violent part of town or a red-light district or whatever it might be, and you didn't want to go there or you didn't want to know about it, well you just didn't go there. The problem is now on the internet all of that is right next to you as well and people are shocked by this. They're suddenly discovering that there are people not like them. They have different attitudes to women, different attitudes to acceptable language, to religion, to class, to sporting teams, to clothing as we've seen in the media lately. Everything.

JOHN STEWART: New South Wales police say they cannot pursue all reports of online abuse and have to prioritise the cases.

SUPT ROB CRITCHLOW, NSW POLICE: Well we put a risk assessment across things that come to us in every case and that goes especially for social media, because people can say a lot of nasty things on social media very quickly, but with no real intention or no capacity to commit the offence. So we would look at their capacity to commit the offence, if they're in the same town or even country and in many cases we've seen, a lot of threats come to us from overseas. So there's really no capacity for that person to carry out a dangerous act after they've made a threat.

JOHN STEWART: The feminist campaigners have refused to be silenced or shut down their social media accounts and say they'll continue to challenge online sexism.

Journalism lecturer Jenna Price says the overseas threats are harmful.

JENNA PRICE, JOURNALISM LECTURER, UTS: So I guess one of the things that concerns me when those threats are being made overseas is that I don't imagine anyone is going to arrive in my house from New Jersey overnight and actually, you know, slice my face up or rape me or murder me, but it's extremely - I mean it's terrifying and when you read message after message like that it's, you know, it starts to hurt you. It's the psychological impacts, it's not just the physical impacts and I just think there needs to be a bit more - a tougher stance by police and also a tougher stance by the social media platforms themselves.

JOHN STEWART: Twitter Australia said in a statement that when content is reported, which violates Twitter rules, the offending accounts are suspended.

John Stewart, Lateline.