Racist Facebook groups have sprung up in the wake of ethnic violence in Sydney's West.

Retaliation attacks were launched against a group of men of Middle-Eastern appearance following the alleged bashing of an Indian student four nights ago in Sydney's Harris Park.

One group dubbed “F--- off we're full” with almost 65,000 members contains a topic “will Indians race-rioters be hunted down...” created immediately after the attacks.

Other threads include “all foreiners (sic) need to be euthanised” “and “Indian stupidism (sic) on a new high”. Many bloggers are members of similar groups including “f--- India” and "kill a Muslim day that would be a good start”.

The groups are flouting State and Commonwealth law, according to Australian National University senior lecturer Dr Matthew Rimmer, and are infringing Facebook policy.

While defamation in online media is “an undefined grey area” according to one government source associated with racial defamation, Rimmer said Facebook could be forced by law to dismantle the groups according to the outcomes of similar court cases.

“It's not too much of a stretch to see the application of [similar cases] to facebook,” Rimmer said.

“Facebook doesn't want to get into censorship but it would want to clear itself of legal ramifications.”

Electronic Frontiers Australia chair Geordie Guy said people joining the groups should be aware of racial hatred and discrimination laws which can apply to online content.

“People you are joining these groups need to be very careful because Australian laws prevent [discrimination] and they aren't constricted to TV or simply stomping your feet in Martin Place,” Guy said.

“There are situations where people are acting illegally and there is scope for police intervention... no reasonable person would have a problem shutting down these groups.”

“There is a real chance they could face legal trouble... it's not like a protest where you are a face in the crowd... it is linked back to everything about you,” he said, speaking of a blogger with links to Microsoft US.

The Australian Communications and Media Authority (ACMA) and other government agencies may investigate complaints by “aggrieved” individuals, but removal of the sites will likely be left to Facebook.

The ACMA will investigate any complaints it receives in relation to Facebook groups. An agency spokesman said the Online Content Scheme under the National Classification Scheme: “does not deal specifically with themes of hate (racial or otherwise), discrimination or vilification, but material may attract a prohibited content classification if it contains - for example - detailed instruction or promotion in matters of crime or violence, very detailed depiction of violence, or the material is considered high in impact and there are no access restrictions”.

Facebook’s Statement of Rights and Responsibilities states that users will not post content that is threatening, hateful... or discriminatory.

Earlier this year a members of a Facebook group faced legal trouble after it posted details about alleged Victorian bush fire arsonist Brendan Sokaluk.