( CNN ) -- For Spanish Prime Minister Jose Luis Rodriguez Zapatero , it was a global virtual black eye . Instead of seeing his photo on the new European Union site , launched this week as Spain took over the presidency , visitors were greeted by Rowan Atkinson 's comic character of Mr. Bean . And if you clicked over to Iranian President Mahmoud Ahmadinejad 's Web site , you 'd see that hackers took him on , too . The text on his site was replaced with a note remarking on the death of `` my favorite singer Michael Jackson '' and `` my favorite voice Neda , '' the woman killed last year during protests over Iranian elections . It ended with a request that God smite Ahmadinejad and `` my favorite dictator [ Ayatollah Ali ] Khamenei in 2010 . '' Millions flocked to mock and clicked to laugh at worldwide leaders -- but security experts say the truth is that the real joke could have been on them . `` The reality is , this is sort of the 21st century form of a street protest , except [ hackers ] have a global reach , and these leaders are being embarrassed in a very public , global way , '' said Danny McPherson , chief security officer and security expert at Ann Arbor Networks . And the embarrassment was ugly . In a technology-age version of residents flooding streets holding signs or drawing glasses on a politician 's poster , Facebook and Twitter users joined in and swarmed the Internet , sharing links to the sites and remarking on the hilarity of the two attacks . But , McPherson said , most of those people probably did n't think about whether they , like the leaders , could have also fallen victim to the hacks . `` It 's a pretty ugly proposition from a risk-management perspective , '' he said . `` The site is being compromised , and not only that , but it can be used to compromise anyone visiting the site , which is far worse than any traditional protest . '' Although it 's unknown whether the sites were hacked merely to send a message or as a goof , McPherson said hackers could just have easily uploaded malware -- malicious software -- that would attack any visitor 's computer . And with the growth of viral Internet videos and pranks , millions of users could easily click on links to the site , especially if it mocks well-known celebrities or leaders and is shared on Facebook or Twitter . And once the word is out about a site being hacked , McPherson said , the ripple effect could be huge . `` With both of those sites , given the political climate in Iran or the EU president site , either of these could have equally been used to distribute malware for journalists or people going to the sites for very valid reasons , '' McPherson said . And hacking of government Web sites , for security intelligence or just for a global joke , is n't as uncommon as you might expect . The antivirus company Symantec said in 2007 that 80 percent of attacks on Web sites happen in the same way as the attacks on the EU and Ahmadinejad sites : through loopholes that allow hackers to upload scripts to change Web sites . And in an age of cyber sit-ins , McPherson says , the threat will only grow until companies continuously work to ensure the security of their sites . Ironically , cybersecurity is one of the issues Zapatero and Spain plan to tackle as part of a digital agenda while it holds the EU presidency . And now , after the hack on the EU Web site , bloggers and commenters around the world have piled on , saying the task may be hefty for Spain , which could n't keep its new site safe from a cyberattack for a week .
Hackers replaced photo of Spain PM with Mr. Bean on new European Union site . Mahmoud Ahmadinejad 's website with message asking God to help Iranian president . Security experts say clicking to laugh at hack and make people vulnerable . Expert : Hacking government sites is ` ` 21st century form of a social protest ''