The article mentions that services already exist that are stealthy enough to fly under the radar:<p><i>&quot;The issue with these methods, however, is that stealthier (and more expensive) like farms — which likely do not rely on fake&#x2F;compromised accounts — can successfully circumvent them, as a result of spreading likes over longer timespans and liking popular pages to mimic normal users. Our recent preliminary study confirms this hypothesis on accounts used by BoostLikes.com, showing that tools similar to those deployed by Facebook (which rely on graph co-clustering) fail to accurately detect fraud.&quot;</i>