There is a fairly large scale and sophisticated florist scam in London using fake Local Guide reviews and shops with fake map listings.
Some of the florist shops are totally false locations, however the clever ones hijack listings for florists which used to exist but went out of business. These shops are harder to identify because the listings were verified by the original genuine owners. Then sometime later when the shop closed, the phone number was edited to redirect the business and fake reviews were added to lend authenticity.
The LG reviewers usually have slightly weird sounding names and they only review other fake florists and give five star reviews. I discovered around 20 spamming LG accounts, there were probably more. I won't identify any LG accounts directly because the Mods will probably redact them even though they're obviously spammers.
I will though link to this mapped business https://goo.gl/maps/idEWEnmpaDt . On initial inspection it looks genuine, a verified listing even with photos from the owner. In July 2014 you can see it on StreetView https://goo.gl/maps/JZa8qGSxE182 and if you look closely you can see the real phone number ending in 3923. However by May 2016 StreetView shows https://goo.gl/maps/TBB4qgzGGP52 the florist has closed and been replaced by a clothes store. I did some further checking and other sources confirm the florist went out of business.
If you now look at the reviews for this florist you can see the top 5 were all in the last month long after the business closed. If you choose to click any of those reviewers names you'll see all their other fake florist reviews. Eventually if you follow the reviewers you'll discover a network of at least 20 spam LG accounts and dozens of fake shops.
Hopefully Map/LG staffers can get these businesses and LG accounts all removed together - and Google can improve its filtering because it is clearly too easy to add spam, which degrades the reputation and reliability of Maps.
Final thought, there really needs to be a direct way to report spammers a bit like there is in MapMaker, but there should also be an open comment field to allow an explanation why the report is being made.
2022
@Gaieus) 
