Website crawler data is different from actual web data(hacking)

Recently i noticed that so many website has been hacked and used as black hat(cloaking) while searching their Website crawler data is different from actual web data. their web site owner still unaware of this until i told. Please check this out. i think hacker run some script in background that makes crawler data is different from actual web data.

One of the site was simmertilldone

If you need some extra details please let me know.