Stalking law welcomed by Plaid MP Elfyn Llwyd
Stalking has become a specific criminal offence in a move to improve victims' safety.
The UK government has introduced two offences of stalking and stalking involving a fear of violence.
It follows a parliamentary inquiry which found the previous laws on harassment and stalking were "not fit for purpose".
The inquiry found that about 120,000 victims, mostly women, were stalked every year.
Plaid Cymru MP Elfyn Llwyd, who chaired the inquiry, told Bethan James of BBC Wales he welcomed the legislation.