when you wake up saturday noon just to see your phone having 10 missed calls from the same unrecognized number, dial back and find it to be a mad client,
complaining about some graphic issues on a site you have nothing to do with.

checking the site; there is nothing wrong so you tell him to clear his browser cache.

he gets mad shouting a silly programmer shall not tell him what to do with his computer and its the site, not his browser.

i ask him if there is the same issue with another browser or computer..
he giggles a little then turn silent..

2mins or so later, he says: i'm gonna let your boss know about this then hangs up..