This is the graph showing valuation of Facebook, Inc. Though it is simple bar graph you can identify many problems in this visual.
http://blogs-images.forbes.com/naomirobbins/files/2011/11/press-005-021.jpg
The very first thing you will find is the truncated vertical axis. Normally we judge values of the bars in the bar graph by its length. Here the second bar appears to be twice as high as of the first bar. One can conclude that valuation is doubled from December to January. Every bar graph needs a zero on its scale.
Second, the horizontal axis is evenly spaced but dates are confusing the reader. There is one bar for December, one for January, none for February, two for March, and so on. Therefore, the trend that results from following the top of the bars is distorted. Mainly, the high valuation of $84 billion appears to hold for a long period, when in fact the total time at this value was less than a month (June 22 to July 19).
Last thing is excessive use of dollar sign on the vertical axis and on data labels. Instead of showing it twenty times in graph, they could have mentioned the scale as ‘dollar units’. These are not serious problems but it does give misleading information.
Source: http://www.forbes.com/sites/naomirobbins/2011/11/17/whats-wrong-with-this-graph/#7acf99f199d4