Takes hold

Having said that, yes we are quite worried about the trend in other countries to suggest Internet service providers and Web sites should be the policemen of the Internet," Morris said.
If the trend takes hold, it could put the companies on the defensive, forcing them to spend more time defending such cases or fending off calls to restrict content in some way.

Could you please explain to me what "takes hold" means here?

I guess it means "comes into effect" though.

Source : http://in.news.yahoo.com/137/20100309/371/tbs-cyber-bullying-cases-put-heat-on-goo.html