Backlinks exploded from few thousand to 23,000

can this cause a penalty?

[Lorel]

I have a client's site whose backlinks were a few thousand until about 6 months ago and rose to 23,000 within a few months. On checking they appear to be mostly from 3 forums he participates in (on other sites) and they appear to be multiplying their pages somehow as he's not that prolific in posing in those forums.

This client has at least 1 competitor trying to ruin his rank so that could be a part of it, but I doubt this can harm his site. At least I hope not. Anyone know for sure?

[skweb]

Nothing to worry. If backlinks could hurt, I will hire a person full time to destroy all my competitors. What does hurt based on the evidence that I have is that you set up a network and then crosslink them to raise number of backlinks.

[theBear]

I'd be more worried if those links went poof after being there a few months. Then it might look like they purchased those links for boosting PR.

Sounds like your client is posting to one of the many forums that produce very similar if not identical information on many urls.