Counter-terrorism police fear that British Islamic preacher Abu Haleema is radicalizing young Australians through his YouTube videos.

The London bus driver has had previous terrorism offences within his own country, and is gaining support within Sydney and Melbourne, according to the Daily Mail. His videos have openly criticized respected Sydney sheikhs Shady Alsuleiman and Wesam Charkawi for their condemnation of last year’s Paris attacks.

“This Wesam Charkawi from Australia,” Haleema addresses in a video published last November, “He’s the man who’s known as the woman-hugging sheikh, all he ever does is come out and condemn atrocities . . . he come out and condemn Paris. How come he never condemned what the French did? When are you going to come out and condemn what they did?”

According to 9 News, Haleema was involved in the radicalization of a British 14-year-old, who had allegedly advised an Aussie teenager to plan an attack on ANZAC Day in Melbourne. He also has suspected links to ISIS recruiter Neil Prakash.

The preacher had his British passport cancelled, according to the Daily Mail, and last year had his Twitter account and Facebook page taken down. The page reportedly had over 7000 followers before being cancelled.

While NSW Police frequently survey social media, counter-terrorism units warn that there is little to be done to lessen Haleema’s impact in Australia. One spokesperson explained to Fairfax that the Internet can make it easy to spread influence from overseas.

However, organisations such as People Against Violent Extremism advocate that the best tool in anti-radicalization is the friends and family of those at risk. Organisation founder Professor Anne Azza Aly spoke to Fairfax Media on the issue:

“I could come up with a video that challenged everything Abu Haleema says,” she explains. “The government could fund a counter-propaganda campaign. But it will never be as effective as when one friend says, “are you mad dude, why are you liking this guy?” That challenge has to happen in a very organic way.”

Abu Haleema is yet to comment on this issue.