I personally think that half a year means a lot to MD and a lot of things happen during that period. So if, for more then 6 month you don't log in or keep connection to the game, you can be removed. Also think at the alts made (hmm Lib entered with all the libs in last 6 months ?) and that are forgotten out there.
In 6 month if you hit 1 log in you are safe from the delete button. Plus, anything can happen in 6 month .i mean..it is half a year , your role will be lost and only few of us will remember that, mostly the veterans, that if you are not an RPC and you survive the delete button for that reason, but even as an RPC you are forgotten.
If someone really wants to come back later will hit the log in at least 1 per week, if not daily for the active days. *points at the veterans that does not play but get the active days*
LE:
As an adding to what Grido said:
[quote]The accounts along with the associate data, creatures, docs, messages, etc, were transfered to a backup table and they will remain there until the next cleanup that will be probably done in two/three month or so.[/quote]
So, only after 8-9 month your account will be deleted complete and with no option to resurrect it. I personally think this is more then reasonable.