Glad I found this topic as I currently have a new trackable I'm about to release. Just added wording in the mission/description about not "taking" it from cache to cache, but rather picking it up and dropping it off for the next person.
I was actually just in the process of looking up caches along the route I'm taking for road trip I'm taking this weekend to determine which location would be best to drop it at when I came across a cache that has been pinged by 12 trackables on the same day. Decided to do some digging and found that all 12 are currently being held "hostage" by the same user and all 12 have the same exact log pattern. Some of these trackables this user has had in their inventory for upwards of 5 years, so that begs the question of is he actually carrying all 12 of these around? I know I certainly would be upset if this trackable I'm about to drop gets hijacked that way. In fact, the last 2 trackable I dropped got lost within 2 months of their initial drop, and I'd be less upset if this new trackable gets lost right away than if its added to someone's collection and gathers thousands of hits like this.
I also find the discussion interesting regarding abandoned trackables in caches. I went trackable hunting last weekend, and between 4 caches with a combined inventory of 5 trackables, only 1 actually had it in there, and that one was dropped the same day I found it, all the others were missing. Funny enough, none of the logs indicated that they were missing despite other users having found the caches in the time being. Granted, I have minimal experience given that I'm an on-again/off-again geocacher with only 23 finds over 7 years, but I still like to periodically lurk on the map and forums to keep up with the community.