Does the word "crutch" imply a temporary support?

If you look at the example provided, liquor provides short-term, temporary relief, and it can be used repeatedly over the long term. Technically the definition is correct, but the word "temporary" can be applied to all things. Nothing lasts forever.

In terms of the internet, the knowledge or learning a child gains from using the internet is temporarily supported by the search - but it does not stay in their heads forever, just as the peace-of-mind brought on by alcohol does not stay forever. It's semantics, nothing more, and if you interpret the definition to mean that the crutch is not reusable indefinitely, it does not seem to match the example.

I would counter that dictionary entry with this one: http://www.macmillandictionary.com/dictionary/american/crutch

I wouldn't say it always implies a short-term situation, though it certainly may. Another dictionary site, merriam-webster.com, defines a crutch as a "prop", which is further defined as "something that props or sustains : support". In the particular sentence cited in the question, if you intended a use meaning merely "support" in a general sense, a helpful learning tool would presumably be a learning support and thus a crutch under this definition (and if I recall correctly, you referred to the Webster's definition in your other question).

It seems that in your use of "crutch" you wanted not to imply a temporal limitation, but also to keep the aspect of inappropriate support. I guess I would say that that seems fair enough, but also that it's a use that is at least open to a range of interpretations. In the sense of being general aids or supports, crutches aren't bad; and if one considers the likely origination of the general meaning of "support" as a metaphor for a physical crutch used as an aid or support in walking (I don't have my print OED to hand or I'd check), it's hard to draw a parallel to use of online resources by students, most of whom don't begin by being crippled or injured in that area.

I wonder if the temporal limitation in that one definition doesn't come from using "crutch" as a synonym for "stopgap", which certainly does imply inappropriateness as well as being short-term. Thesaurus.com, at least, doesn't list them as synonyms for each other, though.

In any event, I would note that the offending poster removed the offending first paragraph from the offending answer prior to this being posted. I would say however that this question is not rendered moot, as it seems capable of repetition, yet otherwise evading review.

ETA: I would also note the third definition given by the Macmillan Dictionary, cited in another answer. It certainly seems that children could suffer long-term effects from finding crutches online, throwing more weight behind the use of the term given in the OP.