The Merriam-Webster Online dictionary give these senses: literally 2 : in effect : virtually <will literally turn the world upside down to combat cruelty or injustice — Norman Cousins> with the following usage note: Since some people take sense 2 to be the opposite of sense 1, it has been frequently criticized as a misuse.
Instead, the use is pure hyperbole intended to gain emphasis, but it often appears in contexts where no additional emphasis is necessary. and for decimate , they have the following senses, with no usage note: decimate 3 a : to reduce drastically especially in number <cholera decimated the population> b : to cause great destruction or harm to <firebombs decimated the city> <an industry decimated by recession>
english.stackexchange.com/users/39/nohat
The New Oxford American Dictionary reports the following note in the usage section: In recent years, an extended use of literally (and also literal ) has become very common,
where literally (or literal ) is used deliberately in nonliteral contexts, for added effect: they bought the car and literally ran it into the ground .
This use can lead to unintentional humorous effects ( we were literally killing ourselves laughing ) and is not acceptable in formal English.
In formal sentences, literally should be used as in
I told him I never wanted to see him again, but I didn't expect him to take it literally.
english.stackexchange.com/users/252/kiamlaluno
With regards to decimation , the original meaning is derived from a practice in the military of Ancient Rome.
Quoted from this page : A unit selected for punishment by decimation was divided into groups of ten; each group drew lots (Sortition), and the soldier on whom the lot fell was executed by his nine comrades, often by stoning or clubbing.
The remaining soldiers were given rations of barley instead of wheat and forced to sleep outside of the Roman encampment.
Because the punishment fell by lot, all soldiers in the group were eligible for execution, regardless of the individual degree of fault, or rank and distinction.
Indeed, this word has been so greatly abused over time (perhaps through ignorance) that its more general meaning of "to destroy" or "to severely harm" is now virtually accepted.
english.stackexchange.com/users/184/Noldorin
They are becoming increasingly common, and it annoys me too.
Since persistent misusers always get their way in the end, I expect literally and decimate to go the way of ultimate and panacea.
english.stackexchange.com/users/305/Brian Hooper
The misuse of literally is not intentional or ironic.
It is used by people who have heard it used properly and thought the speaker meant seriously or absolutely .
If literally can mean either its true meaning or its exact opposite, what word can we use when we actually do want to say someone literally wet themselves laughing?
english.stackexchange.com/users/11767/Jeff
People often use the word "literally" when they really mean "virtually."
As in, "Many people in America have smart phones, netbooks, or laptops virtually attached to their hips.
" Obviously people don't actually have laptops attached to their hips via some leather case with a belt loop, thus you cannot say that they literally have them attached to their hips.
english.stackexchange.com/users/822/parties
Recently I've heard American TV commentators say "[a person] was literally decimated" and "[a Senator] was literally thrown under the bus". In the first case I think the person was not actually 10% killed, but in the second, I believe they meant that 57 members of the US Senate carried #58 onto Constitution Avenue and threw him under a (hopefully moving) bus. Are usages like these normal or acceptable now? I find them grating, myself.
"Literally" and "Decimate" misuse
english.stackexchange.com
<colloquialisms><semantic-shift>
english.stackexchange.com/questions/1863
english.stackexchange.com/users/152/Taldaugion
It appears that this usage of these words is becoming increasingly common and the intended is use if pure hyperbole to gain emphasis. The term "decimated" in this sense is now virtually accepted. These usages are not correct but they do indeed seem to be increasingly common.
It appears that this usage of these words is becoming increasingly common and the intended is use if pure hyperbole to gain emphasis. The term "decimated" in this sense is now virtually accepted. The  New Oxford American Dictionary  reports the following note in the usage section:   In recent years, an extended use of  literally has become very common. With regards to  decimation , the original meaning is derived from a practice in the military of Ancient Rome and this word has been so greatly abused over time that its more general meaning of "to destroy" or "to severely harm" is now virtually accepted. It is used by people who have heard it used properly and thought the speaker meant  seriously  or  absolutely .  People often use the word "literally" when they really mean "virtually."
The Merriam-Webster Online dictionary literally can also mean virtually, with the following usage note:   Since some people take one sense to be the opposite of the other, it has been frequently criticized as a misuse, with some complaining that people often use the word "literally" when they really mean "virtually." Yes, the usage of "literally" in this way is indeed common and is also accepted by the Merriam-Webster Dictionary.
The common usage is just hyperbole and ignores the dictionary meaning. "Decimation" originally meant a punishment in the Roman army but the meaning has been lost. The misuse is increasingly common and former meanings may be lost. The misuse results from misunderstanding. People often use the word "literally" when they really mean "virtually."
The  New Oxford American Dictionary  reports the following note in the usage section:   In recent years, an extended use of  literally has become very common, With regards to  decimation , the original meaning is derived from a practice in the military of Ancient Rome and this word has been so greatly abused over time that its more general meaning of "to destroy" or "to severely harm" is now virtually accepted. It is used by people who have heard it used properly and thought the speaker meant  seriously  or  absolutely .  People often use the word "literally" when they really mean "virtually."
The Merriam-Webster Dictionary does accept the use of "literally" in the figurative sense. The use of the word "literally" to mean "virtually" is common, although its misusage may not be intentional.