Former Cabinet minister Peter Hain has expressed anger after hackers targeted his website.
The Labour MP's site was taken over by the Anonymous group, who left messages criticising the politician's record and supporting WikiLeaks founder Julian Assange.
The Neath MP, an ex-Northern Ireland secretary, said in a statement: "My website was hacked by Anonymous this morning and we are working to restore it as soon as possible.
"After the targeting of several high-profile websites in recent months, this latest incident is yet more evidence that we all need to wake up to the growing cyber security threat in Britain."
Anonymous, a loose collective of computer hackers, has become notorious in recent years for launching denial-of-service attacks against government and corporate websites.