I think the German regulation is quite indicative to the way the legal system treats such matters.
Thus I'll try a bit more free worded, but precise translation:
Als Zahlungsmittel bestimmte Werteinheiten, die in Barter-Clubs, privaten Tauschringen oder anderen Zahlungssystemen gegen realwirtschaftliche Leistungen, Warenlieferungen oder Dienstleistungen geschöpft oder wie z.B. die Bitcoins gegenleistungslos in Computernetzwerken erschaffen werden...
[this regulation is applicable to....]
value units intended to be used for payments, more specifically such value units, which are drawn in barter clubs, private exchange rings or payment systems in exchange to real economic benefits, goods or services. But also applicable to value units, e.g.
Bitcoins, which are created in computer networks without any real economic counter value.
Erlaubnisfrei sind insoweit jedoch nur die Schaffung derartiger Werteinheiten und ihr Einsatz als Zahlungsmittel. Wenn unterdessen diese Werteinheiten ihrerseits selbst zum Handelsgegenstand werden, ist das Geschäft je nach seiner Ausgestaltung als Bankgeschäft nach § 1 Abs. 1 Satz 2 Nrn. 4 oder 10 KWG oder Finanzdienstleistung nach § 1 Abs. 1a Satz 2 Nrn. 1 - 4 KWG zu qualifizieren und steht nach § 32 Abs. 1 KWG grundsätzlich unter Erlaubnisvorbehalt. Diese Werteinheiten sind Rechnungseinheiten und fallen als solche ohne weiteres unter die Finanzinstrumente im Sinne von § 1 Abs. 11 KWG.
There is allowance for everyone, without prior permit, to create such units of value, and to use them for payments.
But, in case these units of value themselves become the the object of trade, then the business doing those transactions is (based on the circumstances) classified either as
banking business, or as
financial service. Such business does by principle need a prior official permission. The reason is: such units of value
are classifiable as accounting units and as such they are automatically classified as financial instruments.
In practice, given such a regulation, the situation is as follows: As long as you don't to anything large scale, your activities can be overlooked generously. Basically, a small fish is at mercy of the authorities noticing him. But as soon as you start more serious business activities and have not applied for the necessary permit
prior to starting any activities, you're automatically suspicious.
And the additional catch is: trying to get the necessary permit requires you to build and present quite some infrastructure, which typically requires you to run a business which can afford to let several employees work solely for creating this infrastructure. At least here in Germany it is definitively this way for any banking business. Financial services have lower requirements, but also more serious limitations.