Some Questions about the Roman Pleblians

[MSB]

Hello all,
I was just reading on the internet that by 130BC the poor were an increasing concern to the ruling classes by 130BC. Sadly it didn't say why, so I was wondering,
Why had the mob become an increasing political and economic concern for the ruling oligarchy by 130BC?


I think that it may have something to do with the politicians taking land from the poor due to the plebleians being unable to maintain them. Is this right.
All help most appreciated,
Avlvs

And at the same time I was also wondering:
Why was the mob becoming an increasing factor in the political life of the republic by 130BC?
Thanks
Avlvs