The weekends seem to be particularly busy.  I think they've figured out that on the weekends, the AR guardians aren't at their posts.

AFAIK... What happens is they send out bots looking for spammable/hackable sites and place them in their database

The ones affecting AR are not so much hackers as they are so called SEO experts trying to generate traffic for their customers who will soon get penalized for using these types of services

Once they have  customer with needs, they grab their bot database and find sites that are easily posted to and there you have it - SPAM

It happens to most sites that offer anonymous postings and also happens to sites that allow free form commenting

I wish I was that lucky! I feel like I am attacked by spam in all directions all the time! Hate it!  And I particularly hate the ones where I unsubscribe but keep getting their stuff for weeks. UGH....

Who knows.  Maybe it's about "budgeting" on the spammer's part.

Maybe they are just different spammers.

I don't think there are filters, BTW...I think they just block the IP address after they find they've spammed.

Wayne and Jean Marie Zuhl They probably get a new IP Address and bombard the site until the AR Staff takes action to block them. You can bet they will be back.

Nope, they find the site & then just hammer it.

AR blocks their IP address & they are bounced. They also close their accounts at the same time.

Perhaps it has to do with the providers of the targeted emails?

Opportunity.   Spammers are clever but not smart.  

At some point, I'm guessing that AR will tweak the spammers.

More efficient to batch up jobs

new shipment of computers after the last IP addresses were blocked?  Just a guess.

Like my good advertising you need to have more than one or two ads

I think there was a hole in the AR net...but I bet they fix it soon!

I think spammers find a hole and exploit that hole for as long as they can Wayne and Jean Marie Zuhl 

Hape spammers and do not want not.

I think it's random.

I am not sure your comment about AR filters is an accurate statement.  The "filter" as I know it ... once reported ... the IP is blocked and the account is deleted.  Holiday weekend ... command post is likely not monitored to the extent it is during the week.

Football season is here.

This has been a bad week for it.  One day, it took getting to page 3 of the Q&A to actually help someone by answering a question!

It occurs in waves for the same reason when someone is robbing a bank vault & the other guy is yelling we got to go & they don't. It becomes addicting. The opportunity is too good to pass up. Spam success is like that

Just when I was getting ready to say...glad they are gone!  One just popped up again.  This is not good. Reported!

I don't but I know someone who does

It seems that a large portion of the spam in a specific wave comes from one spammer or group of spammers.

Spammers can spam if they are using an IP address that is not blocked or they are otherwise able to block other AR filters.

I think Lyn Sims has a great answer - 'this is what they do' being spammers, though fortunately, AR will block them every time (even if it takes awhile, because it's not just one person).  "Annoying" is their game Wayne and Jean Marie Zuhl! 

Never gone for too long just like ants.  Kill a few and their cousins will come for free meal.

Have noticed it is sporadic. Prefer when they leave me alone!

probably for the same reason members here blog everyday for a month and then drop off the face of the earth!!

Every day seems to be a good day for spammers.

Wayne and Jean Marie Zuhl - they are not human, just bots.

When guards are down (or less protected) here in 'Rain at a certain time, they attack!

Once successful, they continue!

It seems to be worse on weekends and holidays...I guess they think staff will not be working to catch it.

Because once you find a weakness in the filters/blocks you exploit it and exploit the heck out of it.  Startup a wordpress blog and enable public comments, you'll see what I'm talking about in no time!

Alan May nailed this one!

No idea.