Under the FAR's this practice is downright illegal.
One needs "common purpose" - so I happen to be flying to the pace you want to go and so we share the "costs" - the costs to an owner are the marginal costs - so fuel, fees, a quid or two for the oil etc. and maybe something for the engine fund.
I am aware of a couple of companies who are trying to do this sort of thing in the US - as a result it now transpires that simply posting on the internet an intent to make a trip and seeing of anyone wants to come along or is going that way is also not legit.
Personally with my airplane, which is maintained to the public standard, I will rent you the airplane even if you can't fly and I'll even give you the numbers of the commercial pilots in the area checked out to fly it - seems this is legit, if you want to share costs no problem - the pilot will fly for free as he crawls his way towards the magic ATPL numbers.
The important thing is the it is insured for this and a commercial pilot is flying it - a random member of the public being flown by a PPL seems to me to open up all sort of problems.
The weird thing is that in the land of the EASA, who I understand clamp down on everything compared to the supposed "open" US authorities, just a notice is possible and not a cause for concern.
Turning to the FAR's again - there is a complicated set of rules even for taking members of the public on quick flights around the circuit for a charity event - minimum numbers of hours are needed, notification of the FSDO etc. but here newly minted PPL can fly someone who will likley not know his abilities and "Mr. PPL" will no doubt feel the 'pressure' to get the punter to the destination - recipe for disaster I think.
As has been said it will be interesting to see what happens when the first death or serious injury occurs.