CCP considers the act of bumping a normal game mechanic, and does not class the bumping of another player’s ship as an exploit. However, persistent targeting of a player with bumping by following them around after they have made an effort to move on to another location can be classified as harassment, and this will be judged on a case by case basis.
Like any CCP pronouncement, further clarification was needed.
If you are reported and we find you actively following around a target without a war to continue bumping a specific player, it will still (at some point) considered harassment, even if you divert your 'attention' a little while doing so. If you have a bone to pick with someone, declare a war and take the risk that your target may actually taste blood and fight back (or finds allies for that part).
Fair enough, with regards to what constitutes harassment. If you have enough of a beef with a miner to follow them system to system, then wardec them already (given NPC corps aren't part of the equation.)
From the miner perspective, though, what constitutes "moving"? CCP clarified further:
While it will involve inconvenience, we will have to see that one actively tried evasion before we consider someone being followed around and harassed. Merely changing belts in the same system or moving a few thousand meters to another asteroid would not qualify in this regard. Ideally you would move to other systems and more than just one or two jumps to avoid being found again quickly, requiring some effort to locate you again (i.e. through locator agents).
More clarification: is harassment looked at by person or character:
If the miner starts changing regions and is still being followed around by the same person that keeps bumping in a regular manner then the intent is pretty clear. Note that I said person, not character, so regional alts will be considered be the same player in this regard.
All of this is more than fair enough, and it's how we all expected CCP to rule on the issue.
Of course, that didn't stop a few people from suggesting that miner bumping become a flaggable offense. I would love to see CCP perform a one-week live trial, flagging any ship that bumps another with a suspect flag. When two ships bump, the bumper is determined to be the one travelling at the greater velocity. Turn that on for a week, and let's see how the carebears react to their request. Oh, the emergent gameplay that would come from this.
Why do people miner bump in the first place? The reaction they get from miners would be one of the big reasons. If you don't react, the bumper will probably move on to another miner. The second big reason, easy to spot the AFK miners (and potential botters).