I looked this up by the way, Collin's Concise Plus says it's a 'combining form', and may be used generally (without even saying the prefix should be Greek as I guessed above) to indicate a phobia of what precedes it.
Probably better to stick to Greek prefixes though - there can't be many words you could choose that wouldn't have an already in use or at least more sensible sounding Greek alternative. 'Internet', perhaps.
